> 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... 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
