Hi, > Martin Sperl <kernel@xxxxxxxxxxxxxxxx> hat am 19. März 2016 um 11:10 > geschrieben: > > > > On 19.03.2016, at 10:52, Stefan Wahren <stefan.wahren@xxxxxxxx> wrote: > > > > Hi, > > > >> Martin Sperl <kernel@xxxxxxxxxxxxxxxx> hat am 19. März 2016 um 08:44 > >> geschrieben: > >> > >> > >> > >>> On 19.03.2016, at 03:17, Eric Anholt <eric@xxxxxxxxxx> wrote: > >>> > >>> Stefan Wahren <stefan.wahren@xxxxxxxx> writes: > >>> > >>>> Hi Eric, > >>>> hi Martin, > >>>> > >>>>> John Youn <John.Youn@xxxxxxxxxxxx> hat am 16. März 2016 um 19:28 > >>>>> geschrieben: > >>>>> > >>>>> > >>>>> On 3/10/2016 11:14 AM, John Youn wrote: > >>>>>> On 3/9/2016 11:06 AM, Doug Anderson wrote: > >>>>>>> > >>>>>>> John: it's pretty clear that there's something taking almost exactly > >>>>>>> 10ms on my system and almost exactly 50ms on Stefan's system. Is > >>>>>>> there some register we could poll to see when this process is done? > >>>>>>> ...or can we look at the dwc2 revision number / feature register and > >>>>>>> detect how long to delay? > >>>>>>> > >> > >> Maybe this difference is related to overclocking settings in the firmware? > >> > >>>>> > >>>>> 1. What is the AHB Clock frequency? Is the AHB Clock gated during > >>>>> Reset? > >>> > >>> Low confidence here as I'm tracing lines across a ton of modules, but it > >>> looks like it comes from the USB AXI clock in peri_image, which is a > >>> gate on the normal 250Mhz APB clock, but nothing should be touching that > >>> gate register as part of USB reset as far as I know. > >>> > >> Isn’t it possible that this clock (probably BCM2835_CLOCK_VPU) is > >> changed by the firmware due to overclocking settings in /boot/config.txt? > > > > i don't use any overclocking settings. > > > > Are you able to reproduce the behavior on your Pi? > > I did not have any problems with USB recently (using 4.5), > so I would not have any idea how to reproduce it. > > Note that I am using it with an AXIS USB-ethernet dongle plus USB-stick > all the time on my Compute Module connected via a tiny hub, > so I wonder if that qualifies as being able to trigger the issue... the probe problem appears after applying John's patch series (it's not in 4.5): [RFT PATCH 1/2] usb: dwc2: Add a 10 ms delay to dwc2_core_reset() [RFT PATCH 2/2] Revert "usb: dwc2: Fix probe problem on bcm2835" Please follow the complete discussion here [1]. [1] - http://marc.info/?l=linux-kernel&m=145711582915801&w=2 > > Martin -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
