Re: [RFT PATCH 2/2] Revert "usb: dwc2: Fix probe problem on bcm2835"

[Stefan Wahren]

Hi Doug,

> Doug Anderson <dianders@xxxxxxxxxxxx> hat am 7. MÃrz 2016 um 22:30
> geschrieben:
>
>
> Stefan,
>
> On Mon, Mar 7, 2016 at 10:40 AM, Stefan Wahren <stefan.wahren@xxxxxxxx> wrote:
> > Hi Doug,
> >
> >> Douglas Anderson <dianders@xxxxxxxxxxxx> hat am 4. MÃrz 2016 um 19:23
> >> geschrieben:
> >>
> >>
> >> This reverts commit 192cb07f7928 ("usb: dwc2: Fix probe problem on
> >> bcm2835") now that we've found the root cause. See the change
> >> titled ("usb: dwc2: Add a 10 ms delay to dwc2_core_reset()").
> >
> > adding a delay of 10 ms after a core reset might be a idea, but applying
> > both
> > patches breaks USB support on RPi :-(
> >
> > I'm getting the wrong register values ...
>
> Ugh. :(
>
> Just out of curiosity, if you loop and time long it takes for the
> registers to get to the right state after reset, what do you get?
> AKA, pick:
>
> https://chromium-review.googlesource.com/331260
>
> ...and let me know what it prints out. On my system I see:
>
> [ 1.990743] dwc2 ff540000.usb: Waited 300001 us, 0x04000400 =>
> 0x04000400, 0x02000800 => 0x02000800
> [ 2.119677] dwc2 ff580000.usb: Waited 9997 us, 0x00100400 =>
> 0x04000400, 0x00000000 => 0x02000800

sure, but this will take some time (weekend).

>
> I believe the difference in behavior is because of the two different
> types of USB controllers (one is OTG and the other is host only).
>
>
> -Doug