[PATCH v2] usb: xhci: Workaround to fix the USB halted endpoint issues

[Marek Vasut]

On 10/17/23 16:16, Tom Rini wrote:
> On Tue, Oct 17, 2023 at 03:48:37PM +0300, Eugen Hristev wrote:
>> On 10/16/23 22:30, Tom Rini wrote:
>>> On Mon, Oct 16, 2023 at 08:34:16AM +0200, Michal Simek wrote:
>>>>
>>>>
>>>> On 10/13/23 17:15, Tom Rini wrote:
>>>>> On Fri, Oct 13, 2023 at 11:11:04AM -0400, Da Xue wrote:
>>>>>> On Fri, Oct 13, 2023 at 7:47 AM Marek Vasut <marex at denx.de> wrote:
>>>>>>>
>>>>>>> On 10/13/23 06:53, Venkatesh Yadav Abbarapu wrote:
>>>>>>>> The xhci host controller driver trying to queue the URB's and it is
>>>>>>>> getting halted at the endpoint, thereby hitting the BUG_ON's.
>>>>>>>> Mostly these kind of random issues are seen on faulty boards.
>>>>>>>> Removing these BUG_ON's from the U-Boot xhci code, as in Linux kernel
>>>>>>>> xhci code BUG_ON/BUG's are removed entirely.
>>>>>>>> Please also note, that BUG_ON() is not recommended any more in the Linux
>>>>>>>> kernel.
>>>>>>>> Similar issue has been observed on TI AM437x board and they created a patch
>>>>>>>> in Linux kernel as below
>>>>>>>> https://patches.linaro.org/project/linux-usb/patch/1390250711-25840-1-git-send-email-balbi@ti.com/
>>>>>>>>
>>>>>>>> Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu at amd.com>
>>>>>>>
>>>>>>> I already explained to Xilinx how to sync the driver with Linux and why
>>>>>>> this is needed to move forward, multiple times, and even provided a
>>>>>>> script which does most of the work automatically, since it is basically
>>>>>>> automated process. Xilinx did not even bother to test the script and
>>>>>>> provide any feedback.
>>>>>>>
>>>>>>> Until that happens, this patch is rejected.
>>>>>>
>>>>>> This patch also causes all of the USB devices on certain platforms to
>>>>>> not be detected:
>>>>>>
>>>>>> scanning bus usb at c9000000 for devices... Device not responding to set address.
>>>>>>
>>>>>>          USB device not accepting new address (error=80000000)
>>>>>
>>>>> Yes, we are stuck at the impasse where the custodian is asking for
>>>>> someone to try and do the re-sync, and everyone else will assist with
>>>>> testing on other platforms, but the re-sync hasn't happened.  Can we
>>>>> please get someone from AMD to attempt the re-sync?
>>>>
>>>> I would like to say that we have someone to do it. But I simply don't have
>>>> that person.
>>>
>>> That is the big problem we face, yes.  Eugen, I think you said you were
>>> going to try and find time to do a re-sync, did you end up getting any?
>>>
>>
>>
>> Hi Tom,
>>
>> Unfortunately at the moment I am working on a different project, so I do not
>> see any perspective to do this in the near future, although I would like to
>> do it and to help.
>> It may be the case that a company investing into an engineer to work on this
>> would be the only way.
>>
>> In any case, do you think Marek would accept doing this incrementally , e.g.
>> now the driver is synced with 3.10, it would be easier to increment to 4.1
>> as a first step ?
> 
> Incremental updates feels like it might be less of a daunting path to
> me, so I'd be agreeable.  Marek?

I am fine with that obviously, in fact, I am fine with anything which is 
not "pick a random patch from the middle of kernel git log, submit it, 
make the driver into a mess of partial patch backports".