[PATCH] ARM: multi_v7_defconfig: enable usb3503

Post by r***@linaro.org
CONFIG_USB_HSIC_USB3503 is needed by exynos5250-arndale for the on-board
asix network controller. Enable it so networking works with
multi_v7_defconfig out of box like it does with exynos_defconfig.
USB3503 is also referenced from exynos4412-odroidu3.dts and
exynos5250-spring.dts so this patch should improve
multi_v7_defconfig on those platforms as well.

Tyler pointed me to this in order to get arndale networking on mainline,
but looks like this might need to be revisited for current mainline.

I tested this and it doesn't work because as of commit 7de7c6717f2c
(ARM: multi_v7_defconfig: Enable Exynos USB PHY) the PHY that this
depends on is built as a module in multi_v7_config, so having this
driver built-in doesn't help. Even after the PHY driver is loaded, this
driver will not detect the hardware.

So instead, I think this driver should be built as a module as well.
Testing that, I can get networking by doing loading both the phy and
this driver after boot:

# modprobe phy-exynos-usb2
# modprobe usb3503

Kevin

Javier Martinez Canillas

2015-06-04 06:38:24 UTC

Hello Kevin,

Tyler pointed me to this in order to get arndale networking on mainline,
but looks like this might need to be revisited for current mainline.
I tested this and it doesn't work because as of commit 7de7c6717f2c
(ARM: multi_v7_defconfig: Enable Exynos USB PHY) the PHY that this
depends on is built as a module in multi_v7_config, so having this
driver built-in doesn't help. Even after the PHY driver is loaded, this
driver will not detect the hardware.
So instead, I think this driver should be built as a module as well.
Testing that, I can get networking by doing loading both the phy and
# modprobe phy-exynos-usb2
# modprobe usb3503

Current policy is to have as much as possible built as a module
in multi_v7_config so regardless of your issue I think that the
patch should be re-spun to change this.

But I wonder why is not working, shouldn't the driver defer and
be probed again once the PHY driver probe succeeds?

Post by Kevin Hilman
Kevin

Best regards,
Javier

Kevin Hilman

2015-06-04 17:47:07 UTC

Post by Javier Martinez Canillas
Hello Kevin,

Tyler pointed me to this in order to get arndale networking on mainline,
but looks like this might need to be revisited for current mainline.
I tested this and it doesn't work because as of commit 7de7c6717f2c
(ARM: multi_v7_defconfig: Enable Exynos USB PHY) the PHY that this
depends on is built as a module in multi_v7_config, so having this
driver built-in doesn't help. Even after the PHY driver is loaded, this
driver will not detect the hardware.
So instead, I think this driver should be built as a module as well.
Testing that, I can get networking by doing loading both the phy and
# modprobe phy-exynos-usb2
# modprobe usb3503

Current policy is to have as much as possible built as a module
in multi_v7_config so regardless of your issue I think that the
patch should be re-spun to change this.

Correct.

Post by Javier Martinez Canillas
But I wonder why is not working, shouldn't the driver defer and
be probed again once the PHY driver probe succeeds?

Yeah, I'm not sure why that isn't working, and didn't look into it.

FWIW, the same problem happens when both are modules. If you modprobe
usb3503 first, then the phy, it doesn't work. You have to load the phy
before the usb3503.

Kevin

Arnd Bergmann

2015-06-05 12:45:51 UTC

Post by Javier Martinez Canillas
But I wonder why is not working, shouldn't the driver defer and
be probed again once the PHY driver probe succeeds?

Yeah, I'm not sure why that isn't working, and didn't look into it.
FWIW, the same problem happens when both are modules. If you modprobe
usb3503 first, then the phy, it doesn't work. You have to load the phy
before the usb3503.

The driver does not try to get a reference to the phy, and it does
not return -EPROBE_DEFER in any circumstance, so I assume it just
runs into an error condition on the first probe and does not
try again.

I don't really understand why the driver registers both an i2c_driver
and a platform_driver, or if that is required, but it may also
complicate getting deferred probing to work here.

Arnd

Riku Voipio

2015-09-14 08:35:56 UTC

Post by Javier Martinez Canillas
But I wonder why is not working, shouldn't the driver defer and
be probed again once the PHY driver probe succeeds?

Yeah, I'm not sure why that isn't working, and didn't look into it.
FWIW, the same problem happens when both are modules. If you modprobe
usb3503 first, then the phy, it doesn't work. You have to load the phy
before the usb3503.

The driver does not try to get a reference to the phy, and it does
not return -EPROBE_DEFER in any circumstance, so I assume it just
runs into an error condition on the first probe and does not
try again.
I don't really understand why the driver registers both an i2c_driver
and a platform_driver, or if that is required, but it may also
complicate getting deferred probing to work here.

Is someone looking into fixing it? Having to load this as module would
be an inconvenience for me, as I like to boot arndale with nfsroot.
Yet I understand that eventually I'll need to use an initrd - so not a
blocker, just grumpy work.

Riku

Krzysztof Kozlowski

2015-09-15 06:50:23 UTC

Post by Riku Voipio

Post by Javier Martinez Canillas
But I wonder why is not working, shouldn't the driver defer and
be probed again once the PHY driver probe succeeds?

Yeah, I'm not sure why that isn't working, and didn't look into it.
FWIW, the same problem happens when both are modules. If you modprobe
usb3503 first, then the phy, it doesn't work. You have to load the phy
before the usb3503.

The driver does not try to get a reference to the phy, and it does
not return -EPROBE_DEFER in any circumstance, so I assume it just
runs into an error condition on the first probe and does not
try again.
I don't really understand why the driver registers both an i2c_driver
and a platform_driver, or if that is required, but it may also
complicate getting deferred probing to work here.

Is someone looking into fixing it?

Fixing what? The PHY issue? The driver not supporting deferred probe?

As for module vs builtin, this is somehow orthogonal for me.
Although modules are preferred on multi_v7 but in case of
boot-essential drivers this should not be a requirement. I also don't
use initrd for network boot... however my root is on MMC. Regardless
if of that I would expect nfsroot to be working on multi_v7 kernel.

From my point of view this is the same case as USB_NET_SMSC75XX or
USB_NET_SMSC95XX, so:
1. Reviewed-by: Krzysztof Kozlowski <***@samsung.com>
2. +1 for CONFIG_PHY_SAMSUNG_USB2=y (regardless of fixing issues in the driver)
3. +1 for fixing the PHY driver

Best regards,
Krzysztof

Sjoerd Simons

2015-09-15 08:17:25 UTC

Post by Krzysztof Kozlowski

Post by Riku Voipio

Post by Javier Martinez Canillas
But I wonder why is not working, shouldn't the driver defer and
be probed again once the PHY driver probe succeeds?

Yeah, I'm not sure why that isn't working, and didn't look into it.
FWIW, the same problem happens when both are modules. If you modprobe
usb3503 first, then the phy, it doesn't work. You have to load the phy
before the usb3503.

The driver does not try to get a reference to the phy, and it does
not return -EPROBE_DEFER in any circumstance, so I assume it just
runs into an error condition on the first probe and does not
try again.
I don't really understand why the driver registers both an
i2c_driver
and a platform_driver, or if that is required, but it may also
complicate getting deferred probing to work here.

Is someone looking into fixing it?

When posting a set of multi_v7 config changes recently to improve how
we support RockChip, Thierry argued the case for building things as
modules as much as possible (even if that means needing an initramfs to
complete boot)[0]..

You're arguing the exact oposite here, while I can see the points in
both arguments (though i'm leaning to agreeing with Thierry) it would
be nice to work out a common policy here as multi_v7 seems to be a
rather big mismatch currently.

Fwiw, looking at the arm64 defconfig it currently has everything built
in. Which isn't too bad as there aren't that many arm64 boards in
mainline yet, but I bet it's going to run into similar issues at some
point.

0: http://lists.infradead.org/pipermail/linux-rockchip/2015-September/0
04280.html

Post by Krzysztof Kozlowski
From my point of view this is the same case as USB_NET_SMSC75XX or
2. +1 for CONFIG_PHY_SAMSUNG_USB2=y (regardless of fixing issues in the driver)
3. +1 for fixing the PHY driver
Best regards,
Krzysztof
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--
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Collabora Ltd.

Krzysztof Kozlowski

2015-09-15 08:34:46 UTC

Post by Krzysztof Kozlowski

Post by Sjoerd Simons

Post by Riku Voipio