On Fri, Jan 08, 2010 at 03:39:22PM -0700, Pete Zaitcev wrote: > When hardware is removed on a Stratus, the system may crash like this: What is a "Stratus"? > > ACPI: PCI interrupt for device 0000:7c:00.1 disabled > Trying to free nonexistent resource <00000000a8000000-00000000afffffff> > Trying to free nonexistent resource <00000000a4800000-00000000a480ffff> > uhci_hcd 0000:7e:1d.0: remove, state 1 > usb usb2: USB disconnect, address 1 > usb 2-1: USB disconnect, address 2 > Unable to handle kernel paging request at 0000000000100100 RIP: > [<ffffffff88021950>] :uhci_hcd:uhci_scan_schedule+0xa2/0x89c > > #4 [ffff81011de17e50] uhci_scan_schedule at ffffffff88021918 > #5 [ffff81011de17ed0] uhci_irq at ffffffff88023cb8 > #6 [ffff81011de17f10] usb_hcd_irq at ffffffff801f1c1f > #7 [ffff81011de17f20] handle_IRQ_event at ffffffff8001123b > #8 [ffff81011de17f50] __do_IRQ at ffffffff800ba749 > > This occurs because an interrupt scans uhci->skelqh, which is > being freed. We do the right thing: disable the interrupts in the > device, and do not do any processing if the interrupt is shared > with other source, but it's possible that another CPU gets > delayed somewhere (e.g. loops) until we started freeing. > > The agreed-upon solution is to wait for interrupts to play out > before proceeding. No other bareers are neceesary. > > A backport of this patch was tested on a 2.6.18 based kernel. > Testing of 2.6.32-based kernels is under way, but it takes us > forever (months) to turn this around. So I think it's a good > patch and we should keep it. Probably should go to the -stable kernels as well, right? thanks, greg k-h -- 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
