On 02/12/2014 04:47 PM, Stefani Seibold wrote: > Am Mittwoch, den 12.02.2014, 10:37 -0500 schrieb Alan Stern: >> 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? >> > Reverting the commit 88ed9fd50e57 solve the problem. Thank you so much. Oops, I'll try to reproduce and investigate. Thanks for the investigations!!! Michael. -- Michael Opdenacker, CEO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com +33 484 258 098 -- 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
