On Wed, 12 Feb 2014, Stefani Seibold wrote: > Hi, > > Am Dienstag, den 11.02.2014, 11:30 -0500 schrieb Alan Stern: > > On Mon, 10 Feb 2014, Stefani Seibold wrote: > > > > > > > I have more information about the bug. I tested with a USB 3.0 > > > > > Expresscard and this works with 3.13. > > > > > > > > > > I also found an old USB 1.1 HUB in my USB gadget box. When i attach the > > > > > USB flash storage to the USB 1.1 hub there is also no problem. > > > > > > > > > > Since the USB 1.1 Hub is attached to the EHCI we can assume that the bug > > > > > is not in the phy support nor in the USB storage driver. > > > > > > > > > > So i thing the bug must be located in the EHCI HC driver. > > > > > > > > Yes, it probably is. Can you build 3.13 with CONFIG_USB_DEBUG enabled? > > > > Maybe some debugging information will show up in the dmesg log and > > > > provide a clue. > > > > > > > > > > I tried the kernel with CONFIG_USB_DEBUG, but i did not get any USB Debug > > > after the computer freeze. > > > > Did anything show up before the freeze? > > > > > After a minute i get the attached output. Sorry i was only able to do screen > > > shot. > > > > It looks like something locked ehci->lock and then never unlocked it. > > But from the screen shot, I can't tell where this happened. > > > > I was able to get the whole kernel messages via netconsole. I also had > enable CONFIG_USB_DEBUG and all kinds of lock detection. > > > When i attach the USB flash memory (sdc), the system freeze and the > fan's of the machine will get noisy. So i think the CPU is 100 % in use. > > I attach the dmesg output and the current kernel config. > > > Also, I tried to reproduce this failure on my own computer, using > > 3.14-rc1, but everything worked correctly. > > > > I will try the 3.14 kernel... But it makes me crazy when a bug > disappears without an explanation. Okay, the debugging info in your dmesg log indicates the cause of the problem. It looks like the bug is related to commit 88ed9fd50e57 (usb/hcd: remove unnecessary local_irq_save) by Michael Opdenacker. (Note: As far as I can tell, the commit itself is okay, but it exposes a bug somewhere else in the kernel.) If you revert that commit from 3.13, does it fix the problem? Alan Stern -- 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
