Am Dienstag, 19. Februar 2013, 15:24:44 schrieb Stephen Warren: > On 02/19/2013 03:17 PM, Marc Dietrich wrote: > > On Tuesday 19 February 2013 23:12:53 Marc Dietrich wrote: > >> Stephen, > >> > >> On Tuesday 19 February 2013 10:03:47 Stephen Warren wrote: > >>> On 02/17/2013 04:48 AM, Marc Dietrich wrote: > >>>> Hi, > >>>> > >>>> I sometimes see unhandled irq from the otg port on my AC100 (kernel > >>>> 3.8.0-rc7). This happens randomly when the a cable is pluged into the > >>>> mini usb port. Seems the port generates an interrupt on probe which > >>>> isn't handled. > >>> > >>> Perhaps Venu can explain this; he is our USB expert. > >>> > >>>> Any ideas? > >>> > >>> I'm slightly confused by your description though; I assume this problem > >>> happens when you boot with a USB cable already plugged in, not when you > >>> first boot the system, then plug in a cable? Is the cable connected to a > >>> host PC, or to a device? > >> > >> the cable is connected to a host PC. It is not shown when connecting > >> after the system has booted. Unfortunately, I cannot generate the error > >> reproducible, e.g. I just tried 10 times and nothing was shown. Maybe > >> just forget it for now if no one has an obvious idea. I'll try to find > >> some reproducable situation and will report back. > > > > arr, just found it: it happens when you load an uboot image via tegrarcm > > first - so this could be a kernel or uboot problem. > > Ah, so that means that the Tegra boot ROM already initialized the USB > port in device mode to receive U-Boot. I assume you're not touching USB > in U-Boot at all, but loading the kernel/... from SD/eMMC. Then, the > kernel initializes/uses USB in host mode (since that's all we support so > far), and then you see the issue. yes, sounds reasonable. > I reproduced this on Harmony. I'll file a bug and assign it to Venu. Thanks! Marc -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
