[PATCH] ARM: multi_v7_defconfig: enable usb3503

[Sjoerd Simons]

On Tue, 2015-09-15 at 15:50 +0900, Krzysztof Kozlowski wrote:
> 2015-09-14 17:35 GMT+09:00 Riku Voipio <riku.voipio at linaro.org>:
> > On 5 June 2015 at 15:45, Arnd Bergmann <arnd at arndb.de> wrote:
> > > On Thursday 04 June 2015 10:47:07 Kevin Hilman wrote:
> > > > 
> > > > > 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.

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



> From my point of view this is the same case as USB_NET_SMSC75XX or
> USB_NET_SMSC95XX, so:
> 1. Reviewed-by: Krzysztof Kozlowski <k.kozlowski at 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
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-- 
Sjoerd Simons <sjoerd.simons at collabora.co.uk>
Collabora Ltd.