Re: [PATCH] k8: Enable legacy irqs with extended cpu ids
Neil Horman <[EMAIL PROTECTED]> writes: > Recently a kdump bug was discovered in which a system would hang inside > calibrate_delay during the booting of the kdump kernel. This was caused by > the > fact that the jiffies counter was not being incremented during timer > calibration. The root cause of this problem was found to be a bios > misconfiguration of the hypertransport bus. On system affected by this hang, > the bios had assigned APIC ids which used extended apic bits (more than the > nominal 4 bit ids's), but failed to configure bit 17 of the hypertransport > transaction config register, which indicated that the mask for the destination > field of interrupt packets accross the ht bus (see section 3.3.9 of > http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26094.PDF). > If a crash occurs on a cpu with an APIC id that extends beyond 4 bits, it will > not recieve interrupts during the kdump kernel boot, and this hang will be the > result. The fix is to add this patch, whcih add an early pci quirk check, to > forcibly enable this bit in the httcfg register. This enables all cpus on a > system to receive interrupts, and allows kdump kernel bootup to procede > normally. > > Regards > Neil > > > Signed-off-by: Neil Horman <[EMAIL PROTECTED]> Acked-by: "Eric W. Biederman" <[EMAIL PROTECTED]> Eric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] k8: Enable legacy irqs with extended cpu ids
Neil Horman [EMAIL PROTECTED] writes: Recently a kdump bug was discovered in which a system would hang inside calibrate_delay during the booting of the kdump kernel. This was caused by the fact that the jiffies counter was not being incremented during timer calibration. The root cause of this problem was found to be a bios misconfiguration of the hypertransport bus. On system affected by this hang, the bios had assigned APIC ids which used extended apic bits (more than the nominal 4 bit ids's), but failed to configure bit 17 of the hypertransport transaction config register, which indicated that the mask for the destination field of interrupt packets accross the ht bus (see section 3.3.9 of http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26094.PDF). If a crash occurs on a cpu with an APIC id that extends beyond 4 bits, it will not recieve interrupts during the kdump kernel boot, and this hang will be the result. The fix is to add this patch, whcih add an early pci quirk check, to forcibly enable this bit in the httcfg register. This enables all cpus on a system to receive interrupts, and allows kdump kernel bootup to procede normally. Regards Neil Signed-off-by: Neil Horman [EMAIL PROTECTED] Acked-by: Eric W. Biederman [EMAIL PROTECTED] Eric -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
