Re: [PATCH v5 3/3] usb: dwc2: Properly account for the force mode delays

John Youn
2016-09-13T19:04:12Z

On 9/13/2016 11:39 AM, Heiko Stübner wrote:
> Am Dienstag, 13. September 2016, 20:07:25 schrieb Stefan Wahren:
>> Hi Heiko,
>>
>>> Heiko Stuebner <heiko@sntech.de> hat am 12. September 2016 um 13:05
>>> geschrieben:
>>>
>>>
>>> Hi Stefan,
>>>
>>> Am Montag, 12. September 2016, 07:20:44 CEST schrieb Stefan Wahren:
>>>>> Heiko Stuebner <heiko@sntech.de> hat am 11. September 2016 um 23:19
>>>>> geschrieben:
>>>>>
>>>>> Am Mittwoch, 7. September 2016, 19:39:43 CEST schrieb John Youn:
>>>>>> When a force mode bit is set and the IDDIG debounce filter is
>>>>>> enabled,
>>>>>> there is a delay for the forced mode to take effect. This delay is
>>>>>> due
>>>>>> to the IDDIG debounce filter and is variable depending on the
>>>>>> platform's
>>>>>> PHY clock speed. To account for this delay we can poll for the
>>>>>> expected
>>>>>> mode.
>>>>>>
>>>>>> On a clear force mode, since we don't know what mode to poll for,
>>>>>> delay
>>>>>> for a fixed 100 ms. This is the maximum delay based on the slowest
>>>>>> PHY
>>>>>> clock speed.
>>>>>>
>>>>>> Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
>>>>>> Signed-off-by: John Youn <johnyoun@synopsys.com>
>>>>>> ---
>>>>>
>>>>> [...]
>>>>>
>>>>>> @@ -475,12 +478,6 @@ void dwc2_force_dr_mode(struct dwc2_hsotg
>>>>>> *hsotg)
>>>>>>
>>>>>> __func__, hsotg->dr_mode);
>>>>>>
>>>>>> break;
>>>>>>
>>>>>> }
>>>>>>
>>>>>> -
>>>>>> - /*
>>>>>> - * NOTE: This is required for some rockchip soc based
>>>>>> - * platforms.
>>>>>> - */
>>>>>> - msleep(50);
>>>>>>
>>>>>> }
>>>>>
>>>>> sorry for not finding the time to test your subsequent versions, but
>>>>> this
>>>>> still
>>>>> acts up on my Rockchip boards, as I'm still running into errors like
>>>>>
>>>>> [ 4.875570] usb usb2-port1: connect-debounce failed
>>>>
>>>> could you please name the relevant DTS file of the affected boards?
>>>
>>> So far I've been able to see that on
>>>
>>> rk3188-radxarock
>>> rk3036-kylin
>>>
>>> both on host-only dwc2 controllers.
>>
>> thanks, does patch 1 & 2 already have a negative effect on these
>> controllers?
>
> nope, patches 1+2 alone are ok and only the msleep(50) going away causes
> problems. I'm back home now, so I'll hopefully have time to check host-only
> vs. otg dwc2 controllers tomorrow as well.
>

Ok, thanks for testing Heiko.

Given that, let's try to fix this in the next -rc (or before) because
I think the Raspberry Pi needs the other parts of that last patch. We
can just revert the msleep(50) if needed.

I'll also try to get my hands on a rockchip platform. I think that
will help the testing along.

Regards,
John

_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org