[PATCH] ARM: dts: imx6qdl-udoo: Disable usbh1 to avoid kernel hang

[Fabio Estevam]

Hi Markus,

On Sun, Feb 11, 2018 at 11:47 AM, Markus Rathgeb <maggu2810 at gmail.com> wrote:
> Hi Fabio,
>
> have you seen my message from
>
> 2018-01-20 10:14 GMT+01:00 Markus Rathgeb <maggu2810 at gmail.com>:
>>
>>
>> I tested the patch that sets usbh1's status to disable using the
>> kernel 4.13 that previously hangs.
>> I confirm the disabled usb host allows to boot my imx6q-udoo board.
>>
>> Tested-by: Markus Rathgeb <maggu2810 at gmail.com>
>
> or missed I some further messages on that topic?

Shawn will probably apply the patch in the 4.16 cycle.

>
> With your changes the board will boot again, so a step forward (but
> USB will not working).

Correct.

>
> I recently read the "Linux Kernel Release Model"
> (http://kroah.com/log/blog/2018/02/05/linux-kernel-release-model/) and
> stumbled about that sentence: "The Linux kernel community has promised
> its userbase that no upgrade will ever break anything that is
> currently working in a previous release."
> I used the Udoo board a long time for my USB printer to access it over
> the network. So USB has been working in a release but does not work
> anymore.
> "Regressions do happen, but those are the highest priority bugs and
> are either quickly fixed, or the change that caused the regression is
> quickly reverted from the Linux kernel tree."

In the case of Udoo USB it has only worked by "luck".

A decent implementation requires to be able to drive USB hub clock and
reset lines.

Unfortunately this is still not supported in mainline kernel.

> So, can we expect that USB will be working soon again or are such
> boards an exception to that overcome?

Peter Chen has been working to fix the USB issue (his last series was
v17 as far as a recall).

Feel free to take his series, address the maintainers feedback and re-post it.

Regards,

Fabio Estevam