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. I reproduced this on Harmony. I'll file a bug and assign it to Venu. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
