Re: [PATCH 2/4] usb: host: xhci: Introduce one new 'usb3_slow_suspend' member for xhci private data

[Baolin Wang]

Hi Felipe,

On 18 August 2016 at 21:42, Felipe Balbi <balbi@xxxxxxxxxx> wrote:
>
> Hi Baolin,
>
> Baolin Wang <baolin.wang@xxxxxxxxxx> writes:
>>>>>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
>>>>>> index e2e2487..162f17c 100644
>>>>>> --- a/drivers/usb/host/xhci-plat.c
>>>>>> +++ b/drivers/usb/host/xhci-plat.c
>>>>>> @@ -250,6 +250,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
>>>>>>                       (pdata && pdata->usb3_lpm_capable))
>>>>>>               xhci->quirks |= XHCI_LPM_SUPPORT;
>>>>>>
>>>>>> +     if (pdata && pdata->usb3_slow_suspend)
>>>>>> +             xhci->quirks |= XHCI_SLOW_SUSPEND;
>>>>>
>>>>> I remember having a discussion about this with Paul Z and it turned out
>>>>> that we really didn't need SLOW_SUSPEND. Can you describe further in
>>>>> what situation you need this quirk?
>>>>
>>>> On my dwc3 platform, xhci suspend will be failed if we have not
>>>> enabled XHCI_SLOW_SUSPEND quirk.
>>>
>>> fail how? What error do you see? Do you have some traces of what's
>>> happening? Did you try figuring out if this is, perhaps, caused by some
>>> call ordering which is wrong? Perhaps disabling PHYs too early or
>>> something like that?
>>
>> It shows the warning "WARN: xHC CMD_RUN timeout" when running
>> xhci_suspend(). If I enbale XHCI_SLOW_SUSPEND quirk, then it can work
>> well. I did not try to figure out other things, due to I think the
>> dwc3 need XHCI_SLOW_SUSPEND quirk. But I can re-try to figure out if
>> there are other issues if you still believe that dwc3 does not need
>> XHCI_SLOW_SUSPEND quirk. Thanks.
>
> When I discussed this with Paul Z, he told me there was no known
> DWC3 SoC that really needed SLOW_SUSPEND, so it's likely to be a bug in
> either xhci or dwc3.
>
> Please try to track this down. I would start looking at ordering with
> PHY poweroff or something like that.

OK. Thanks.

-- 
Baolin.wang
Best Regards