On Fri, Apr 05, 2013 at 03:25:54PM -0400, Neil Horman wrote: > A few years back intel published a spec update: > http://www.intel.com/content/dam/doc/specification-update/5520-and-5500-chipset-ioh-specification-update.pdf > > For the 5520 and 5500 chipsets which contained an errata (specificially errata > 53), which noted that these chipsets can't properly do interrupt remapping, and > as a result the recommend that interrupt remapping be disabled in bios. While > many vendors have a bios update to do exactly that, not all do, and of course > not all users update their bios to a level that corrects the problem. As a > result, occasionally interrupts can arrive at a cpu even after affinity for that > interrupt has be moved, leading to lost or spurrious interrupts (usually > characterized by the message: > kernel: do_IRQ: 7.71 No irq handler for vector (irq -1) > > There have been several incidents recently of people seeing this error, and > investigation has shown that they have system for which their BIOS level is such > that this feature was not properly turned off. As such, it would be good to > give them a reminder that their systems are vulnurable to this problem. > > Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx> > CC: Prarit Bhargava <prarit@xxxxxxxxxx> > CC: Don Zickus <dzickus@xxxxxxxxxx> > CC: Don Dutile <ddutile@xxxxxxxxxx> > CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > CC: Asit Mallick <asit.k.mallick@xxxxxxxxx> > CC: David Woodhouse <dwmw2@xxxxxxxxxxxxx> > CC: linux-pci@xxxxxxxxxxxxxxx > --- > > Change notes: > > v2) > > * Moved the quirk to the x86 arch, since consensus seems to be that the 55XX > chipset series is x86 only. I decided however to keep the quirk as a regular > quirk, not an early_quirk. Early quirks have no way currently to determine if > BIOS has properly disabled the feature in the iommu, at least not without > significant hacking, and since its quite possible this will be a short lived > quirk, should Don Z's workaround code prove successful (and it looks like it may > well), I don't think that necessecary. > > * Removed the WARNING banner from the quirk, and added the HW_ERR token to the > string, I opted to leave the newlines in place however, as I really couldnt > find a way to keep the text on a single line is still legible from a code > perspective. I think theres enough language in there that using cscope on just > about any substring however will turn it up, and again, this may be a short > lived quirk. > > v3) > > * Removed defines from pci_ids.h, and used direct id values as per request from > Bjorn. > > v4) > > * Converted pr_warn to WARN_TAINT(TAINT_FIRMWARE_WORKAROUND) as per David > Woodhouse > > v5) > > * Moved check to an early quirk, and flagged the broken chip, so we could > reasonably disable irq remapping during bootup. Self NAK, sorry, I've got extra water in the quirks file left over from my move. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
