Messages in this thread | | | Date | Tue, 6 Oct 2009 06:44:01 +0200 | From | Nick Piggin <> | Subject | Re: Patch "USB: Work around BIOS bugs by quiescing USB controllers earlier" causes MCEs |
| |
On Fri, Oct 02, 2009 at 09:28:32PM +0200, Mikael Pettersson wrote: > Mikael Pettersson writes: > > Nick Piggin writes: > > > Hi, > > > > > > Your patch db8be50c4307dac2b37305fc59c8dc0f978d09ea is causing my > > > ia64 Altix system to die with an MCE in early boot. > > > > The same commit has been confirmed by two people on the ARM list > > to cause boot failures on two different Intel XScale IOP machines. > > The machines have serial consoles, but only show > > > > Uncompressing Linux... done. Booting the kernel. > > > > before they hang. > > I've just investigated this on one of my ARM boxes that this commit kills. > > The commit changed quirk_usb_early_handoff to be a FIXUP_HEADER, which > caused it to be invoked during the early stages of the platform's PCI > init (arch/arm/kernel/bios32.c). quirk_usb_handoff_uhci() gets a bogus > I/O base address, passes that down to uhci_reset_hc(), causing a kernel > page fault in the first "outw(UHCI_USBCMD_HCRESET, base + UHCI_USBCMD);", > causing the kernel to oops. > > (All this occurs before the serial console works, so I had to add a > platform-specific puts() and lots of tracing statements.) > > Changing this quirk back to a FIXUP_FINAL allows the platform's PCI > init to complete. Later on the generic pci_init() calls the quirk, > which now gets the correct I/O base address, and the outw()s in > uhci_reset_hc() don't fail.
Thanks for this, I guess we await David's response.
| |