Discussion:
[PATCH 1/6] mmc: sdhci: add platfrom get_max_timeout hook
(too old to reply)
Dong Aisheng
2013-12-10 12:56:03 UTC
Permalink
Currently the max_discard_to is simply got by (1 << 27) / host->timeout_clk
which is assumed to be the maximum timeout value, however, some platforms
maximum timeout counter may not be 1 << 27, e.g. i.MX uSDHC is 1 << 28.
Thus 1 << 27 may not be correct for such platforms.

It is also possible that other platforms may have different problems.
To be flexible, we add a get_max_timeout hook to get the correct
maximum timeout value for these platforms.

Signed-off-by: Dong Aisheng <***@freescale.com>
Reported-by: Ed Sutter <***@alcatel-lucent.com>
---
drivers/mmc/host/sdhci.c | 5 ++++-
drivers/mmc/host/sdhci.h | 1 +
2 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index bd8a098..464d42c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2930,7 +2930,10 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;

- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
+ else
+ mmc->max_discard_to = (1 << 27) / host->timeout_clk;

mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;

diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 0a3ed01..1591cbb 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -281,6 +281,7 @@ struct sdhci_ops {
unsigned int (*get_max_clock)(struct sdhci_host *host);
unsigned int (*get_min_clock)(struct sdhci_host *host);
unsigned int (*get_timeout_clock)(struct sdhci_host *host);
+ unsigned int (*get_max_timeout)(struct sdhci_host *host);
int (*platform_bus_width)(struct sdhci_host *host,
int width);
void (*platform_send_init_74_clocks)(struct sdhci_host *host,
--
1.7.2.rc3


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Dong Aisheng
2013-12-10 12:56:04 UTC
Permalink
The default sdhci code use the 1 << 27 as the max timeout counter to
to calculate the max_discard_to, however it's not correct for uSDHC
since its the max counter is 1 << 28.
Implement esdhc_get_max_timeout to handle it correctly.

Signed-off-by: Dong Aisheng <***@freescale.com>
Reported-by: Ed Sutter <***@alcatel-lucent.com>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 461a4c3..97b35e1 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -859,6 +859,15 @@ static int esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs)
return esdhc_change_pinstate(host, uhs);
}

+unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct pltfm_imx_data *imx_data = pltfm_host->priv;
+ u32 max_to = esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;
+
+ return max_to / (esdhc_pltfm_get_max_clock(host) / 1000);
+}
+
static struct sdhci_ops sdhci_esdhc_ops = {
.read_l = esdhc_readl_le,
.read_w = esdhc_readw_le,
@@ -871,6 +880,7 @@ static struct sdhci_ops sdhci_esdhc_ops = {
.get_ro = esdhc_pltfm_get_ro,
.platform_bus_width = esdhc_pltfm_bus_width,
.set_uhs_signaling = esdhc_set_uhs_signaling,
+ .get_max_timeout = esdhc_get_max_timeout,
};

static const struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
--
1.7.2.rc3


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Shawn Guo
2013-12-11 01:58:25 UTC
Permalink
Post by Dong Aisheng
The default sdhci code use the 1 << 27 as the max timeout counter to
to calculate the max_discard_to, however it's not correct for uSDHC
since its the max counter is 1 << 28.
Implement esdhc_get_max_timeout to handle it correctly.
---
drivers/mmc/host/sdhci-esdhc-imx.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 461a4c3..97b35e1 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -859,6 +859,15 @@ static int esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs)
return esdhc_change_pinstate(host, uhs);
}
+unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
static?

Shawn
Post by Dong Aisheng
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct pltfm_imx_data *imx_data = pltfm_host->priv;
+ u32 max_to = esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;
+
+ return max_to / (esdhc_pltfm_get_max_clock(host) / 1000);
+}
+
static struct sdhci_ops sdhci_esdhc_ops = {
.read_l = esdhc_readl_le,
.read_w = esdhc_readw_le,
@@ -871,6 +880,7 @@ static struct sdhci_ops sdhci_esdhc_ops = {
.get_ro = esdhc_pltfm_get_ro,
.platform_bus_width = esdhc_pltfm_bus_width,
.set_uhs_signaling = esdhc_set_uhs_signaling,
+ .get_max_timeout = esdhc_get_max_timeout,
};
static const struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
--
1.7.2.rc3
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Dong Aisheng
2013-12-10 12:56:06 UTC
Permalink
The default sdhci driver write 0xE into timeout counter register to
set the maximum timeout. The value is not correct for uSDHC since the
max counter value for uSDHC is 0xF.
Instead of using common timeout code in sdhci, we implement esdhc_set_timeout
to handle the difference between eSDHC and uSDHC.

Signed-off-by: Dong Aisheng <***@freescale.com>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 97b35e1..c24cb23 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -868,6 +868,16 @@ unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
return max_to / (esdhc_pltfm_get_max_clock(host) / 1000);
}

+void esdhc_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct pltfm_imx_data *imx_data = pltfm_host->priv;
+
+ /* use maximum timeout counter */
+ sdhci_writeb(host, esdhc_is_usdhc(imx_data) ? 0xF : 0xE,
+ SDHCI_TIMEOUT_CONTROL);
+}
+
static struct sdhci_ops sdhci_esdhc_ops = {
.read_l = esdhc_readl_le,
.read_w = esdhc_readw_le,
@@ -881,6 +891,7 @@ static struct sdhci_ops sdhci_esdhc_ops = {
.platform_bus_width = esdhc_pltfm_bus_width,
.set_uhs_signaling = esdhc_set_uhs_signaling,
.get_max_timeout = esdhc_get_max_timeout,
+ .set_timeout = esdhc_set_timeout,
};

static const struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
--
1.7.2.rc3


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Shawn Guo
2013-12-11 02:17:17 UTC
Permalink
Post by Dong Aisheng
The default sdhci driver write 0xE into timeout counter register to
set the maximum timeout. The value is not correct for uSDHC since the
max counter value for uSDHC is 0xF.
Instead of using common timeout code in sdhci, we implement esdhc_set_timeout
to handle the difference between eSDHC and uSDHC.
---
drivers/mmc/host/sdhci-esdhc-imx.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 97b35e1..c24cb23 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -868,6 +868,16 @@ unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
return max_to / (esdhc_pltfm_get_max_clock(host) / 1000);
}
+void esdhc_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
static?

Shawn
Post by Dong Aisheng
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct pltfm_imx_data *imx_data = pltfm_host->priv;
+
+ /* use maximum timeout counter */
+ sdhci_writeb(host, esdhc_is_usdhc(imx_data) ? 0xF : 0xE,
+ SDHCI_TIMEOUT_CONTROL);
+}
+
static struct sdhci_ops sdhci_esdhc_ops = {
.read_l = esdhc_readl_le,
.read_w = esdhc_readw_le,
@@ -881,6 +891,7 @@ static struct sdhci_ops sdhci_esdhc_ops = {
.platform_bus_width = esdhc_pltfm_bus_width,
.set_uhs_signaling = esdhc_set_uhs_signaling,
.get_max_timeout = esdhc_get_max_timeout,
+ .set_timeout = esdhc_set_timeout,
};
static const struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
--
1.7.2.rc3
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Dong Aisheng
2013-12-11 03:08:46 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
The default sdhci driver write 0xE into timeout counter register to
set the maximum timeout. The value is not correct for uSDHC since the
max counter value for uSDHC is 0xF.
Instead of using common timeout code in sdhci, we implement esdhc_set_timeout
to handle the difference between eSDHC and uSDHC.
---
drivers/mmc/host/sdhci-esdhc-imx.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 97b35e1..c24cb23 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -868,6 +868,16 @@ unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
return max_to / (esdhc_pltfm_get_max_clock(host) / 1000);
}
+void esdhc_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
static?
Sorry, i missed it when do copy&paste.
Will update it in v2 with another same issue you pointed.

Regards
Dong Aisheng
Post by Shawn Guo
Shawn
Post by Dong Aisheng
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct pltfm_imx_data *imx_data = pltfm_host->priv;
+
+ /* use maximum timeout counter */
+ sdhci_writeb(host, esdhc_is_usdhc(imx_data) ? 0xF : 0xE,
+ SDHCI_TIMEOUT_CONTROL);
+}
+
static struct sdhci_ops sdhci_esdhc_ops = {
.read_l = esdhc_readl_le,
.read_w = esdhc_readw_le,
@@ -881,6 +891,7 @@ static struct sdhci_ops sdhci_esdhc_ops = {
.platform_bus_width = esdhc_pltfm_bus_width,
.set_uhs_signaling = esdhc_set_uhs_signaling,
.get_max_timeout = esdhc_get_max_timeout,
+ .set_timeout = esdhc_set_timeout,
};
static const struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
--
1.7.2.rc3
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Dong Aisheng
2013-12-10 12:56:05 UTC
Permalink
Currently the common code assume 0xE is the maximum timeout counter
value and use it to write into the timeout counter register.
However, it's fairly possible that the different SoCs may have
different register layout on the timeout counter register.
That means 0xE may not be the correct maximum timeout value, then
the 0xE becomes meaningless.

To be flexible, this patch provides another approach for platforms
to set the correct timeout on their way.

Signed-off-by: Dong Aisheng <***@freescale.com>
---
drivers/mmc/host/sdhci.c | 19 ++++++++++++++-----
drivers/mmc/host/sdhci.h | 2 ++
2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 464d42c..4cc3bd6 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -726,19 +726,28 @@ static void sdhci_set_transfer_irqs(struct sdhci_host *host)
sdhci_clear_set_irqs(host, dma_irqs, pio_irqs);
}

-static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
{
u8 count;
+
+ if (host->ops->set_timeout) {
+ host->ops->set_timeout(host, cmd);
+ } else {
+ count = sdhci_calc_timeout(host, cmd);
+ sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
+ }
+}
+
+static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+{
u8 ctrl;
struct mmc_data *data = cmd->data;
int ret;

WARN_ON(host->data);

- if (data || (cmd->flags & MMC_RSP_BUSY)) {
- count = sdhci_calc_timeout(host, cmd);
- sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
- }
+ if (data || (cmd->flags & MMC_RSP_BUSY))
+ sdhci_set_timeout(host, cmd);

if (!data)
return;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 1591cbb..a4851a0 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -282,6 +282,8 @@ struct sdhci_ops {
unsigned int (*get_min_clock)(struct sdhci_host *host);
unsigned int (*get_timeout_clock)(struct sdhci_host *host);
unsigned int (*get_max_timeout)(struct sdhci_host *host);
+ void (*set_timeout)(struct sdhci_host *host,
+ struct mmc_command *cmd);
int (*platform_bus_width)(struct sdhci_host *host,
int width);
void (*platform_send_init_74_clocks)(struct sdhci_host *host,
--
1.7.2.rc3


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Shawn Guo
2013-12-11 02:16:48 UTC
Permalink
Post by Dong Aisheng
Currently the common code assume 0xE is the maximum timeout counter
value and use it to write into the timeout counter register.
However, it's fairly possible that the different SoCs may have
different register layout on the timeout counter register.
That means 0xE may not be the correct maximum timeout value, then
the 0xE becomes meaningless.
To be flexible, this patch provides another approach for platforms
to set the correct timeout on their way.
---
drivers/mmc/host/sdhci.c | 19 ++++++++++++++-----
drivers/mmc/host/sdhci.h | 2 ++
2 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 464d42c..4cc3bd6 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -726,19 +726,28 @@ static void sdhci_set_transfer_irqs(struct sdhci_host *host)
sdhci_clear_set_irqs(host, dma_irqs, pio_irqs);
}
-static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
{
u8 count;
+
+ if (host->ops->set_timeout) {
+ host->ops->set_timeout(host, cmd);
+ } else {
+ count = sdhci_calc_timeout(host, cmd);
+ sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
+ }
+}
+
+static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+{
u8 ctrl;
struct mmc_data *data = cmd->data;
int ret;
WARN_ON(host->data);
- if (data || (cmd->flags & MMC_RSP_BUSY)) {
- count = sdhci_calc_timeout(host, cmd);
From what I read the commit log, I think it might be more appropriate to
patch sdhci_calc_timeout() like the following?

if (host->quirks & SDHCI_QUIRK_BROKEN_TIMEOUT_VAL)
if (host->ops->get_max_timeout)
return host->ops->get_max_timeout(host);
else
return 0xE;

Shawn
Post by Dong Aisheng
- sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
- }
+ if (data || (cmd->flags & MMC_RSP_BUSY))
+ sdhci_set_timeout(host, cmd);
if (!data)
return;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 1591cbb..a4851a0 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -282,6 +282,8 @@ struct sdhci_ops {
unsigned int (*get_min_clock)(struct sdhci_host *host);
unsigned int (*get_timeout_clock)(struct sdhci_host *host);
unsigned int (*get_max_timeout)(struct sdhci_host *host);
+ void (*set_timeout)(struct sdhci_host *host,
+ struct mmc_command *cmd);
int (*platform_bus_width)(struct sdhci_host *host,
int width);
void (*platform_send_init_74_clocks)(struct sdhci_host *host,
--
1.7.2.rc3
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Dong Aisheng
2013-12-11 03:03:31 UTC
Permalink
Post by Dong Aisheng
Post by Dong Aisheng
Currently the common code assume 0xE is the maximum timeout counter
value and use it to write into the timeout counter register.
However, it's fairly possible that the different SoCs may have
different register layout on the timeout counter register.
That means 0xE may not be the correct maximum timeout value, then
the 0xE becomes meaningless.
To be flexible, this patch provides another approach for platforms
to set the correct timeout on their way.
---
drivers/mmc/host/sdhci.c | 19 ++++++++++++++-----
drivers/mmc/host/sdhci.h | 2 ++
2 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 464d42c..4cc3bd6 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -726,19 +726,28 @@ static void sdhci_set_transfer_irqs(struct sdhci_host *host)
sdhci_clear_set_irqs(host, dma_irqs, pio_irqs);
}
-static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
{
u8 count;
+
+ if (host->ops->set_timeout) {
+ host->ops->set_timeout(host, cmd);
+ } else {
+ count = sdhci_calc_timeout(host, cmd);
+ sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
+ }
+}
+
+static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+{
u8 ctrl;
struct mmc_data *data = cmd->data;
int ret;
WARN_ON(host->data);
- if (data || (cmd->flags & MMC_RSP_BUSY)) {
- count = sdhci_calc_timeout(host, cmd);
From what I read the commit log, I think it might be more appropriate to
patch sdhci_calc_timeout() like the following?
if (host->quirks & SDHCI_QUIRK_BROKEN_TIMEOUT_VAL)
if (host->ops->get_max_timeout)
return host->ops->get_max_timeout(host);
else
return 0xE;
The return val of sdhci_calc_timeout is the register value to be
written into timeout counter register.
host->ops->get_max_timeout returns the max timeout in miliseconds directly.
So we can not do like that here.
They're two concepts.

Regards
Dong Aisheng
Post by Dong Aisheng
Shawn
Post by Dong Aisheng
- sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
- }
+ if (data || (cmd->flags & MMC_RSP_BUSY))
+ sdhci_set_timeout(host, cmd);
if (!data)
return;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 1591cbb..a4851a0 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -282,6 +282,8 @@ struct sdhci_ops {
unsigned int (*get_min_clock)(struct sdhci_host *host);
unsigned int (*get_timeout_clock)(struct sdhci_host *host);
unsigned int (*get_max_timeout)(struct sdhci_host *host);
+ void (*set_timeout)(struct sdhci_host *host,
+ struct mmc_command *cmd);
int (*platform_bus_width)(struct sdhci_host *host,
int width);
void (*platform_send_init_74_clocks)(struct sdhci_host *host,
--
1.7.2.rc3
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Shawn Guo
2013-12-11 03:18:55 UTC
Permalink
Post by Dong Aisheng
Post by Dong Aisheng
Post by Dong Aisheng
+static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+{
u8 ctrl;
struct mmc_data *data = cmd->data;
int ret;
WARN_ON(host->data);
- if (data || (cmd->flags & MMC_RSP_BUSY)) {
- count = sdhci_calc_timeout(host, cmd);
From what I read the commit log, I think it might be more appropriate to
patch sdhci_calc_timeout() like the following?
if (host->quirks & SDHCI_QUIRK_BROKEN_TIMEOUT_VAL)
if (host->ops->get_max_timeout)
return host->ops->get_max_timeout(host);
else
return 0xE;
The return val of sdhci_calc_timeout is the register value to be
written into timeout counter register.
host->ops->get_max_timeout returns the max timeout in miliseconds directly.
So we can not do like that here.
They're two concepts.
I did not make my comment clear. The .get_max_timeout() is not the one
you defined in patch #1 any more, but something like the following for
esdhc driver, which returns correct timeout value not milliseconds.

unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct pltfm_imx_data *imx_data = pltfm_host->priv;

return esdhc_is_usdhc(imx_data) ? 0xF : 0xE;

}

Does that match the problem you described in the commit log better?

Shawn

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Dong Aisheng
2013-12-11 03:35:17 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
Post by Dong Aisheng
Post by Dong Aisheng
+static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
+{
u8 ctrl;
struct mmc_data *data = cmd->data;
int ret;
WARN_ON(host->data);
- if (data || (cmd->flags & MMC_RSP_BUSY)) {
- count = sdhci_calc_timeout(host, cmd);
From what I read the commit log, I think it might be more appropriate to
patch sdhci_calc_timeout() like the following?
if (host->quirks & SDHCI_QUIRK_BROKEN_TIMEOUT_VAL)
if (host->ops->get_max_timeout)
return host->ops->get_max_timeout(host);
else
return 0xE;
The return val of sdhci_calc_timeout is the register value to be
written into timeout counter register.
host->ops->get_max_timeout returns the max timeout in miliseconds directly.
So we can not do like that here.
They're two concepts.
I did not make my comment clear. The .get_max_timeout() is not the one
you defined in patch #1 any more, but something like the following for
esdhc driver, which returns correct timeout value not milliseconds.
unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct pltfm_imx_data *imx_data = pltfm_host->priv;
return esdhc_is_usdhc(imx_data) ? 0xF : 0xE;
}
Does that match the problem you described in the commit log better?
This actually is the register value, not the max timeout counter value.
Then you may want define the API as:
unsigned int (*get_max_timeout_val)(struct sdhci_host *host);
But i don't think it's necessary to do the max timeout setting in two steps.
First, deinfe a API to get the max timeout counter val,
Second, write this val into register.
Why not simply implement .set_timeout and handle the details in
platform specific
host driver respectively?

Furthermore, this API does not help for the patch#1 issue.


Regards
Dong Aisheng
Post by Shawn Guo
Shawn
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Shawn Guo
2013-12-11 03:48:26 UTC
Permalink
Post by Dong Aisheng
This actually is the register value, not the max timeout counter value.
unsigned int (*get_max_timeout_val)(struct sdhci_host *host);
Yes, something like that.
Post by Dong Aisheng
But i don't think it's necessary to do the max timeout setting in two steps.
First, deinfe a API to get the max timeout counter val,
Second, write this val into register.
Why not simply implement .set_timeout and handle the details in
platform specific
host driver respectively?
Well, that's how sdhci host driver is structured. Doing so leaves the
least details to platform driver, and calling sdhci_writeb() to access
SDHCI_TIMEOUT_CONTROL in sdhci-esdhc-imx seems a layer violation to me.
Post by Dong Aisheng
Furthermore, this API does not help for the patch#1 issue.
Oh, they two different issues, and should be addressed by different
hooks.

Shawn
Dong Aisheng
2013-12-11 05:03:43 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
This actually is the register value, not the max timeout counter value.
unsigned int (*get_max_timeout_val)(struct sdhci_host *host);
Yes, something like that.
Post by Dong Aisheng
But i don't think it's necessary to do the max timeout setting in two steps.
First, deinfe a API to get the max timeout counter val,
Second, write this val into register.
Why not simply implement .set_timeout and handle the details in
platform specific
host driver respectively?
Well, that's how sdhci host driver is structured. Doing so leaves the
least details to platform driver, and calling sdhci_writeb() to access
SDHCI_TIMEOUT_CONTROL in sdhci-esdhc-imx seems a layer violation to me.
The current sdhci-esdhci-imx already does something like that.
You can search SDHCI_* in the code.
It just reuses the register offset definition in sdhci,
It's not the layer violation.

Regards
Dong Aisheng
Post by Shawn Guo
Post by Dong Aisheng
Furthermore, this API does not help for the patch#1 issue.
Oh, they two different issues, and should be addressed by different
hooks.
Shawn
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Shawn Guo
2013-12-11 06:04:15 UTC
Permalink
Post by Dong Aisheng
Post by Shawn Guo
Post by Dong Aisheng
This actually is the register value, not the max timeout counter value.
unsigned int (*get_max_timeout_val)(struct sdhci_host *host);
Yes, something like that.
Post by Dong Aisheng
But i don't think it's necessary to do the max timeout setting in two steps.
First, deinfe a API to get the max timeout counter val,
Second, write this val into register.
Why not simply implement .set_timeout and handle the details in
platform specific
host driver respectively?
Well, that's how sdhci host driver is structured. Doing so leaves the
least details to platform driver, and calling sdhci_writeb() to access
SDHCI_TIMEOUT_CONTROL in sdhci-esdhc-imx seems a layer violation to me.
The current sdhci-esdhci-imx already does something like that.
You can search SDHCI_* in the code.
It just reuses the register offset definition in sdhci,
It's not the layer violation.
I do not understand why we have to do this SDHCI_TIMEOUT_CONTROL setup
in our sdhci-esdhc-imx driver, when sdhci driver is already structured
to do it in its way. All we need is a hook to give the correct
max_timeout_val.

Shawn

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Dong Aisheng
2013-12-17 06:49:10 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
Post by Shawn Guo
Post by Dong Aisheng
This actually is the register value, not the max timeout counter value.
unsigned int (*get_max_timeout_val)(struct sdhci_host *host);
Yes, something like that.
Post by Dong Aisheng
But i don't think it's necessary to do the max timeout setting in two steps.
First, deinfe a API to get the max timeout counter val,
Second, write this val into register.
Why not simply implement .set_timeout and handle the details in
platform specific
host driver respectively?
Well, that's how sdhci host driver is structured. Doing so leaves the
least details to platform driver, and calling sdhci_writeb() to access
SDHCI_TIMEOUT_CONTROL in sdhci-esdhc-imx seems a layer violation to me.
The current sdhci-esdhci-imx already does something like that.
You can search SDHCI_* in the code.
It just reuses the register offset definition in sdhci,
It's not the layer violation.
I do not understand why we have to do this SDHCI_TIMEOUT_CONTROL setup
in our sdhci-esdhc-imx driver, when sdhci driver is already structured
to do it in its way. All we need is a hook to give the correct
max_timeout_val.
Because i don't think sdhci_calc_timeout is still meaningful anymore for a
SDHCI_QUIRK_BROKEN_TIMEOUT_VAL anymore.
The only thing you reply sdhci to do is set a max_timeout.

And i don't think it's necessary to use a hook to get max_timeout_val first,
then use this val to write into register later to do the max_timeout
setting work.
It's perfect fine to let the platform .set_timeout to do it directly.
And we already have .get_max_timeout_count hook, i don't want
.get_max_timeout_val again.

There's another important reason that .set_timeout provides other platforms
host controller ability to set timeout based on their way if they want.
The sdhci should have this capability since it is common case just like
.set_clock and etc.
e.g. imx5. the timeout count setting is different when DDR is enabled.
(Though we still not add DDR support for mx5)
Then we must need such hook to do specific IMX timeout setting instead
of using common sdhci timeout setting.

Regards
Dong Aisheng
Post by Shawn Guo
Shawn
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Dong Aisheng
2013-12-10 12:56:08 UTC
Permalink
The timeout clock for uSDHC is SDCLK, so it's reasonable to use
the actual_clock to calculate the max timeout.

Signed-off-by: Dong Aisheng <***@freescale.com>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index c24cb23..83236d3 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -865,7 +865,8 @@ unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
struct pltfm_imx_data *imx_data = pltfm_host->priv;
u32 max_to = esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;

- return max_to / (esdhc_pltfm_get_max_clock(host) / 1000);
+ return host->mmc->actual_clock ?
+ max_to / (host->mmc->actual_clock / 1000) : 0;
}

void esdhc_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
--
1.7.2.rc3


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Dong Aisheng
2013-12-10 12:56:07 UTC
Permalink
For host controllers using SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK, since the card
clock is changed dynamically for different cards, it does not make sense
to use the maximum host clock to calculate max_discard_to which may lead
the max_discard_to to be much smaller than its capbility and affect the card
discard performance a lot.
e.g. the host clock is 200Mhz, but the card is working on 50Mhz. Then the
max_discard_to is only 1/4 of its real capbility.

In this patch, it uses the actual_clock to calculate the max_discard_to
dynamically as long as a new clock speed is set.

Tested with a high speed SDHC card shows:
Originally:
mmc1: new high speed SDHC card at address aaaa
mmc1: calculated max. discard sectors 49152 for timeout 1355 ms
Now:
mmc1: new high speed SDHC card at address aaaa
mmc1: calculated max. discard sectors 712704 for timeout 5422 ms
The max_discard_sectors will increase a lot which will also improve discard
performance a lot.

The one known limitation of this approach is that it does not cover the special
case for user changes the clock via sysfs, since the max_discard_to is only
initialised for one time during the mmc queue init.

Signed-off-by: Dong Aisheng <***@freescale.com>
---
drivers/mmc/host/sdhci.c | 27 +++++++++++++++++++++------
1 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 4cc3bd6..9be8a79 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1143,14 +1143,14 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
unsigned long timeout;

if (clock && clock == host->clock)
- return;
+ goto out;

host->mmc->actual_clock = 0;

if (host->ops->set_clock) {
host->ops->set_clock(host, clock);
if (host->quirks & SDHCI_QUIRK_NONSTANDARD_CLOCK)
- return;
+ goto out;
}

sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
@@ -1249,6 +1249,19 @@ clock_set:

out:
host->clock = clock;
+
+ /* update timeout_clk and max_discard_to once the SDCLK is changed */
+ if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK && clock) {
+ host->timeout_clk = host->mmc->actual_clock ?
+ host->mmc->actual_clock / 1000 :
+ host->clock / 1000;
+ if (host->ops->get_max_timeout)
+ host->mmc->max_discard_to =
+ host->ops->get_max_timeout(host);
+ else
+ host->mmc->max_discard_to = (1 << 27) /
+ host->timeout_clk;
+ }
}

static inline void sdhci_update_clock(struct sdhci_host *host)
@@ -2939,10 +2952,12 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;

- if (host->ops->get_max_timeout)
- mmc->max_discard_to = host->ops->get_max_timeout(host);
- else
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
+ else
+ mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ }

mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;
--
1.7.2.rc3


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Shawn Guo
2013-12-11 03:01:49 UTC
Permalink
Post by Dong Aisheng
For host controllers using SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK, since the card
clock is changed dynamically for different cards, it does not make sense
to use the maximum host clock to calculate max_discard_to which may lead
the max_discard_to to be much smaller than its capbility and affect the card
discard performance a lot.
e.g. the host clock is 200Mhz, but the card is working on 50Mhz. Then the
max_discard_to is only 1/4 of its real capbility.
In this patch, it uses the actual_clock to calculate the max_discard_to
dynamically as long as a new clock speed is set.
mmc1: new high speed SDHC card at address aaaa
mmc1: calculated max. discard sectors 49152 for timeout 1355 ms
mmc1: new high speed SDHC card at address aaaa
mmc1: calculated max. discard sectors 712704 for timeout 5422 ms
The max_discard_sectors will increase a lot which will also improve discard
performance a lot.
The one known limitation of this approach is that it does not cover the special
case for user changes the clock via sysfs, since the max_discard_to is only
initialised for one time during the mmc queue init.
---
drivers/mmc/host/sdhci.c | 27 +++++++++++++++++++++------
1 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 4cc3bd6..9be8a79 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1143,14 +1143,14 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
unsigned long timeout;
if (clock && clock == host->clock)
- return;
+ goto out;
I do not quite understand this change. Why do we need to recalculate
max_discard_to if the clock does not change since the last time that
the function is called?

Shawn
Post by Dong Aisheng
host->mmc->actual_clock = 0;
if (host->ops->set_clock) {
host->ops->set_clock(host, clock);
if (host->quirks & SDHCI_QUIRK_NONSTANDARD_CLOCK)
- return;
+ goto out;
}
sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
host->clock = clock;
+
+ /* update timeout_clk and max_discard_to once the SDCLK is changed */
+ if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK && clock) {
+ host->timeout_clk = host->mmc->actual_clock ?
+ host->clock / 1000;
+ if (host->ops->get_max_timeout)
+ host->mmc->max_discard_to =
+ host->ops->get_max_timeout(host);
+ else
+ host->mmc->max_discard_to = (1 << 27) /
+ host->timeout_clk;
+ }
}
static inline void sdhci_update_clock(struct sdhci_host *host)
@@ -2939,10 +2952,12 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;
- if (host->ops->get_max_timeout)
- mmc->max_discard_to = host->ops->get_max_timeout(host);
- else
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
+ else
+ mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ }
mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;
--
1.7.2.rc3
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Dong Aisheng
2013-12-11 03:13:38 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
For host controllers using SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK, since the card
clock is changed dynamically for different cards, it does not make sense
to use the maximum host clock to calculate max_discard_to which may lead
the max_discard_to to be much smaller than its capbility and affect the card
discard performance a lot.
e.g. the host clock is 200Mhz, but the card is working on 50Mhz. Then the
max_discard_to is only 1/4 of its real capbility.
In this patch, it uses the actual_clock to calculate the max_discard_to
dynamically as long as a new clock speed is set.
mmc1: new high speed SDHC card at address aaaa
mmc1: calculated max. discard sectors 49152 for timeout 1355 ms
mmc1: new high speed SDHC card at address aaaa
mmc1: calculated max. discard sectors 712704 for timeout 5422 ms
The max_discard_sectors will increase a lot which will also improve discard
performance a lot.
The one known limitation of this approach is that it does not cover the special
case for user changes the clock via sysfs, since the max_discard_to is only
initialised for one time during the mmc queue init.
---
drivers/mmc/host/sdhci.c | 27 +++++++++++++++++++++------
1 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 4cc3bd6..9be8a79 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1143,14 +1143,14 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
unsigned long timeout;
if (clock && clock == host->clock)
- return;
+ goto out;
I do not quite understand this change. Why do we need to recalculate
max_discard_to if the clock does not change since the last time that
the function is called?
Good catch.
It's safe to return directly here.
Will update in v2.

Regards
Dong Aisheng
Post by Shawn Guo
Shawn
Post by Dong Aisheng
host->mmc->actual_clock = 0;
if (host->ops->set_clock) {
host->ops->set_clock(host, clock);
if (host->quirks & SDHCI_QUIRK_NONSTANDARD_CLOCK)
- return;
+ goto out;
}
sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
host->clock = clock;
+
+ /* update timeout_clk and max_discard_to once the SDCLK is changed */
+ if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK && clock) {
+ host->timeout_clk = host->mmc->actual_clock ?
+ host->clock / 1000;
+ if (host->ops->get_max_timeout)
+ host->mmc->max_discard_to =
+ host->ops->get_max_timeout(host);
+ else
+ host->mmc->max_discard_to = (1 << 27) /
+ host->timeout_clk;
+ }
}
static inline void sdhci_update_clock(struct sdhci_host *host)
@@ -2939,10 +2952,12 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;
- if (host->ops->get_max_timeout)
- mmc->max_discard_to = host->ops->get_max_timeout(host);
- else
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
+ else
+ mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ }
mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;
--
1.7.2.rc3
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Shawn Guo
2013-12-11 04:05:12 UTC
Permalink
Post by Dong Aisheng
static inline void sdhci_update_clock(struct sdhci_host *host)
@@ -2939,10 +2952,12 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;
Since max_discard_to calculation below will not happen for
SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK case, does it still make sense to
keep the above code?

Or put it in the other way, if we keep the above code and do not make
the change below, will there be any problem besides the max_discard_to
initialization plays for nothing?

All in all, I'm just confused why we keep the above code and make the
change below at the same time.

Shawn
Post by Dong Aisheng
- if (host->ops->get_max_timeout)
- mmc->max_discard_to = host->ops->get_max_timeout(host);
- else
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
+ else
+ mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ }
mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;
--
1.7.2.rc3
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Dong Aisheng
2013-12-11 05:06:41 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
static inline void sdhci_update_clock(struct sdhci_host *host)
@@ -2939,10 +2952,12 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;
Since max_discard_to calculation below will not happen for
SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK case, does it still make sense to
keep the above code?
Right, i missed to remove it.
Will update in v2.
Post by Shawn Guo
Or put it in the other way, if we keep the above code and do not make
the change below, will there be any problem besides the max_discard_to
initialization plays for nothing?
All in all, I'm just confused why we keep the above code and make the
change below at the same time.
THe max_discard_to should be dynamically updated for
SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK
when changing the clock, so we can remove above lines.

Regards
Dong Aisheng
Post by Shawn Guo
Shawn
Post by Dong Aisheng
- if (host->ops->get_max_timeout)
- mmc->max_discard_to = host->ops->get_max_timeout(host);
- else
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
+ else
+ mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ }
mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;
--
1.7.2.rc3
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Shawn Guo
2013-12-11 01:56:43 UTC
Permalink
Post by Dong Aisheng
Currently the max_discard_to is simply got by (1 << 27) / host->timeout_clk
which is assumed to be the maximum timeout value, however, some platforms
maximum timeout counter may not be 1 << 27, e.g. i.MX uSDHC is 1 << 28.
Thus 1 << 27 may not be correct for such platforms.
It is also possible that other platforms may have different problems.
To be flexible, we add a get_max_timeout hook to get the correct
maximum timeout value for these platforms.
---
drivers/mmc/host/sdhci.c | 5 ++++-
drivers/mmc/host/sdhci.h | 1 +
2 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index bd8a098..464d42c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2930,7 +2930,10 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
Does "timeout" conceptually equals to "discard_to"? If not, we might
want to write it in the either form below to avoid messing these two
concepts.

mmc->max_discard_to = host->ops->get_max_timeout(host) / host->timeout_clk;

or

mmc->max_discard_to = host->ops->get_max_discard_to(host);

I guess you may want to go for the second one.

Shawn
Post by Dong Aisheng
+ else
+ mmc->max_discard_to = (1 << 27) / host->timeout_clk;
mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 0a3ed01..1591cbb 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -281,6 +281,7 @@ struct sdhci_ops {
unsigned int (*get_max_clock)(struct sdhci_host *host);
unsigned int (*get_min_clock)(struct sdhci_host *host);
unsigned int (*get_timeout_clock)(struct sdhci_host *host);
+ unsigned int (*get_max_timeout)(struct sdhci_host *host);
int (*platform_bus_width)(struct sdhci_host *host,
int width);
void (*platform_send_init_74_clocks)(struct sdhci_host *host,
--
1.7.2.rc3
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Dong Aisheng
2013-12-11 03:00:03 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
Currently the max_discard_to is simply got by (1 << 27) / host->timeout_clk
which is assumed to be the maximum timeout value, however, some platforms
maximum timeout counter may not be 1 << 27, e.g. i.MX uSDHC is 1 << 28.
Thus 1 << 27 may not be correct for such platforms.
It is also possible that other platforms may have different problems.
To be flexible, we add a get_max_timeout hook to get the correct
maximum timeout value for these platforms.
---
drivers/mmc/host/sdhci.c | 5 ++++-
drivers/mmc/host/sdhci.h | 1 +
2 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index bd8a098..464d42c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2930,7 +2930,10 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
Does "timeout" conceptually equals to "discard_to"? If not, we might
want to write it in the either form below to avoid messing these two
concepts.
No, they're two concepts but the max_discard_to equals to the max timeout value
the host supports.
Post by Shawn Guo
mmc->max_discard_to = host->ops->get_max_timeout(host) / host->timeout_clk;
or
mmc->max_discard_to = host->ops->get_max_discard_to(host);
I guess you may want to go for the second one.
The original way looks ok to me.
Platform host driver does not need to know detail about discard,
just tell the max timeout value it supports is ok.
Common sdhci driver will handle it well.

Regards
Dong Aisheng
Post by Shawn Guo
Shawn
Post by Dong Aisheng
+ else
+ mmc->max_discard_to = (1 << 27) / host->timeout_clk;
mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 0a3ed01..1591cbb 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -281,6 +281,7 @@ struct sdhci_ops {
unsigned int (*get_max_clock)(struct sdhci_host *host);
unsigned int (*get_min_clock)(struct sdhci_host *host);
unsigned int (*get_timeout_clock)(struct sdhci_host *host);
+ unsigned int (*get_max_timeout)(struct sdhci_host *host);
int (*platform_bus_width)(struct sdhci_host *host,
int width);
void (*platform_send_init_74_clocks)(struct sdhci_host *host,
--
1.7.2.rc3
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Shawn Guo
2013-12-11 03:12:56 UTC
Permalink
Post by Dong Aisheng
Post by Shawn Guo
Post by Dong Aisheng
@@ -2930,7 +2930,10 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
Does "timeout" conceptually equals to "discard_to"? If not, we might
want to write it in the either form below to avoid messing these two
concepts.
No, they're two concepts but the max_discard_to equals to the max timeout value
the host supports.
Does it? Shouldn't max_discard_to equals to max_timeout_value / timeout_clk?
Post by Dong Aisheng
Post by Shawn Guo
mmc->max_discard_to = host->ops->get_max_timeout(host) / host->timeout_clk;
or
mmc->max_discard_to = host->ops->get_max_discard_to(host);
I guess you may want to go for the second one.
The original way looks ok to me.
Platform host driver does not need to know detail about discard,
just tell the max timeout value it supports is ok.
Common sdhci driver will handle it well.
Well, looking at the patch #2, esdhc_get_max_timeout() returns

max_to / (esdhc_pltfm_get_max_clock(host) / 1000)

not just the max timeout value - max_to, so your platform host driver
is knowing and handling the details about discard_ro, i.e. the
discard_ro has to be max_timeout_value / timeout_clk.

Shawn

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Dong Aisheng
2013-12-11 03:20:59 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
Post by Shawn Guo
Post by Dong Aisheng
@@ -2930,7 +2930,10 @@ int sdhci_add_host(struct sdhci_host *host)
if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
host->timeout_clk = mmc->f_max / 1000;
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
Does "timeout" conceptually equals to "discard_to"? If not, we might
want to write it in the either form below to avoid messing these two
concepts.
No, they're two concepts but the max_discard_to equals to the max timeout value
the host supports.
Does it? Shouldn't max_discard_to equals to max_timeout_value / timeout_clk?
Yes, you probably are confused that get_max_timeout return timeout in
miliseconds directly.
Do not need to do get_max_timeout(host) /timeout_clk.
Post by Shawn Guo
Post by Dong Aisheng
Post by Shawn Guo
mmc->max_discard_to = host->ops->get_max_timeout(host) / host->timeout_clk;
or
mmc->max_discard_to = host->ops->get_max_discard_to(host);
I guess you may want to go for the second one.
The original way looks ok to me.
Platform host driver does not need to know detail about discard,
just tell the max timeout value it supports is ok.
Common sdhci driver will handle it well.
Well, looking at the patch #2, esdhc_get_max_timeout() returns
max_to / (esdhc_pltfm_get_max_clock(host) / 1000)
not just the max timeout value - max_to, so your platform host driver
is knowing and handling the details about discard_ro, i.e. the
discard_ro has to be max_timeout_value / timeout_clk.
No, the max_to is the max timeout counter value, you need to divide it
by the timeout clock
to get the timeout time.
The defined of this API is return the max timeout value in
miliseconds, so you need to
divide the clock by 1000.
None of these handles the detail bout discard_to.

Regards
Dong Aisheng
Post by Shawn Guo
Shawn
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Shawn Guo
2013-12-11 03:56:56 UTC
Permalink
Post by Dong Aisheng
No, the max_to is the max timeout counter value, you need to divide it
by the timeout clock
to get the timeout time.
The defined of this API is return the max timeout value in
miliseconds, so you need to
divide the clock by 1000.
None of these handles the detail bout discard_to.
Let me start it over again. Here is basically what your patch does.

- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);

The only thing that does not work for you in the existing code is the
(1 << 27) part, right?

If so, why not just create a platform hook to return the correct thing
for you platform, i.e. (1 << 28)?

if (host->ops->get_max_timeout)
mmc->max_discard_to = host->ops->hook_foo(host);

unsigned int esdhc_hook_foo(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct pltfm_imx_data *imx_data = pltfm_host->priv;

return esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;
}

Such patch will be ease to be understood and less offensive to the
existing code, no?

Shawn

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Dong Aisheng
2013-12-11 04:59:55 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
No, the max_to is the max timeout counter value, you need to divide it
by the timeout clock
to get the timeout time.
The defined of this API is return the max timeout value in
miliseconds, so you need to
divide the clock by 1000.
None of these handles the detail bout discard_to.
Let me start it over again. Here is basically what your patch does.
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
The only thing that does not work for you in the existing code is the
(1 << 27) part, right?
If so, why not just create a platform hook to return the correct thing
for you platform, i.e. (1 << 28)?
if (host->ops->get_max_timeout)
mmc->max_discard_to = host->ops->hook_foo(host);
unsigned int esdhc_hook_foo(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct pltfm_imx_data *imx_data = pltfm_host->priv;
return esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;
}
Such patch will be ease to be understood and less offensive to the
existing code, no?
The example you give is not correct here.
The max timeout counter returned by esdhc_hook_foo can not be simpled assigned
to max_discard_to which is timeout in miliseconds.

Actually what i did is like the way you said:
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
+ else
+ mmc->max_discard_to = (1 << 27) / host->timeout_clk;

+unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct pltfm_imx_data *imx_data = pltfm_host->priv;
+ u32 max_to = esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;
+
+ return max_to / (esdhc_pltfm_get_max_clock(host) / 1000);
+}

Regards
Dong Aisheng
Post by Shawn Guo
Shawn
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Shawn Guo
2013-12-11 05:55:27 UTC
Permalink
Post by Dong Aisheng
Post by Shawn Guo
Post by Dong Aisheng
No, the max_to is the max timeout counter value, you need to divide it
by the timeout clock
to get the timeout time.
The defined of this API is return the max timeout value in
miliseconds, so you need to
divide the clock by 1000.
None of these handles the detail bout discard_to.
Let me start it over again. Here is basically what your patch does.
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
The only thing that does not work for you in the existing code is the
(1 << 27) part, right?
If so, why not just create a platform hook to return the correct thing
for you platform, i.e. (1 << 28)?
if (host->ops->get_max_timeout)
mmc->max_discard_to = host->ops->hook_foo(host);
unsigned int esdhc_hook_foo(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct pltfm_imx_data *imx_data = pltfm_host->priv;
return esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;
}
Such patch will be ease to be understood and less offensive to the
existing code, no?
The example you give is not correct here.
Sorry. Yes, there is a error in my example code. What about this?

mmc->max_discard_to = host->ops->hook_foo ? host->ops->hook_foo(host) : 1 << 27;
mmc->max_discard_to /= host->timeout_clk;

Shawn

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Dong Aisheng
2013-12-17 06:15:59 UTC
Permalink
Post by Shawn Guo
Post by Dong Aisheng
Post by Shawn Guo
Post by Dong Aisheng
No, the max_to is the max timeout counter value, you need to divide it
by the timeout clock
to get the timeout time.
The defined of this API is return the max timeout value in
miliseconds, so you need to
divide the clock by 1000.
None of these handles the detail bout discard_to.
Let me start it over again. Here is basically what your patch does.
- mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+ if (host->ops->get_max_timeout)
+ mmc->max_discard_to = host->ops->get_max_timeout(host);
The only thing that does not work for you in the existing code is the
(1 << 27) part, right?
If so, why not just create a platform hook to return the correct thing
for you platform, i.e. (1 << 28)?
if (host->ops->get_max_timeout)
mmc->max_discard_to = host->ops->hook_foo(host);
unsigned int esdhc_hook_foo(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct pltfm_imx_data *imx_data = pltfm_host->priv;
return esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;
}
Such patch will be ease to be understood and less offensive to the
existing code, no?
The example you give is not correct here.
Sorry. Yes, there is a error in my example code. What about this?
mmc->max_discard_to = host->ops->hook_foo ? host->ops->hook_foo(host) : 1 << 27;
mmc->max_discard_to /= host->timeout_clk;
Actually i did like this for FSL internal tree.
Just because one concern that other SoCs may have different case
e.g. for imx5, the max count becomes 1 << 26 when DDR is enabled.
Then this way becomes unwork.
And i don't know how many other special SoC exists working on different way.
So i prefer-ed a more flexible way in this patch.

However, after one more thought, since the issue of the example i gave
can be addressed with my patch 5 (able to update max_discard_to when
DDR enabled).
And we already have timeout_clk hook, so it seems we could also go this way.

Regards
Dong Aisheng
Post by Shawn Guo
Shawn
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