Solved 4.14 regression: USB support on A20/sun* (Cubietruck, BananaPi)

Solved 4.14 regression: USB support on A20/sun* (Cubietruck, BananaPi)

[Christoph Biedl]

Just a heads-up to avoid more people lose hours in debugging:

After upgrading from 4.9 to 4.14 I noticed USB support was broken on
my Allwinner A20 boards like Cubietruck and first generation BananaPi.
There is simply no output of the lsusb command, and subsequently no
connected USB devices are detected.

Bisecting led to

commit 6254a6a94489c4be717f757bec7d3a372cba1b6e
Author: Arnd Bergmann <arnd@arndb.de>
Date:   Thu Apr 27 21:11:48 2017 +0200

    power: supply: axp20x_usb_power: add IIO dependency

which already happened in the 4.12 development. Turns out after that
commit "make oldconfig" will silently drop CONFIG_AXP20X_POWER unless
CONFIG_IIO is set - but CONFIG_AXP20X_POWER is needed for USB on these
boards.

Solution: Enable CONFIG_IIO, but no particular driver is required. I'm
not aware whether it's possible to provide a smoother upgrade path in
Kconfig, "selects" instead of "depends" might have been an option.

    Christoph, two more 4.14 regressions to go

Re: Solved 4.14 regression: USB support on A20/sun* (Cubietruck, BananaPi)

[Greg KH]

On Thu, Dec 28, 2017 at 11:08:27AM +0100, Christoph Biedl wrote:
> Just a heads-up to avoid more people lose hours in debugging:
> 
> After upgrading from 4.9 to 4.14 I noticed USB support was broken on
> my Allwinner A20 boards like Cubietruck and first generation BananaPi.
> There is simply no output of the lsusb command, and subsequently no
> connected USB devices are detected.
> 
> Bisecting led to
> 
> commit 6254a6a94489c4be717f757bec7d3a372cba1b6e
> Author: Arnd Bergmann <arnd@arndb.de>
> Date:   Thu Apr 27 21:11:48 2017 +0200
> 
>     power: supply: axp20x_usb_power: add IIO dependency
> 
> which already happened in the 4.12 development. Turns out after that
> commit "make oldconfig" will silently drop CONFIG_AXP20X_POWER unless
> CONFIG_IIO is set - but CONFIG_AXP20X_POWER is needed for USB on these
> boards.
> 
> Solution: Enable CONFIG_IIO, but no particular driver is required. I'm
> not aware whether it's possible to provide a smoother upgrade path in
> Kconfig, "selects" instead of "depends" might have been an option.

Try letting the authors of that patch know about this please.

thanks,

greg k-h