On 28/09/13 20:26, Martin wrote: > AMD > E-450 APU with Radeon(tm) HD Graphics AuthenticAMD GNU/Linux
Just in case someone else stumbles across this thread due to a related problem for my particular motherboard... There appears to be a fatal hardware bug for the interrupt line deassert for a PCIe to PCI Bridge chip: ASMedia Technology Inc. ASM1083/1085 PCIe to PCI Bridge (rev 01) See the thread on https://lkml.org/lkml/2012/1/30/216 For that chip, the interrupt line is not always deasserted for PCI interrupts. The hardware fault appears to be fixed in ASM1083 rev 03. Unfortunately, there is no useful OS workaround possible for rev 01. Hence, the PCI interrupts are unusable for ASM1083 rev01 ? :-( In brief, this means that the PCI card slots on the motherboard cannot be used for any hardware that might generate an interrupt. That means pretty much all normal PCI cards. (The PCIe card slots are fine.) For my own example, there does not appear to be any other devices using that bridge chip. The only concern is for the sound chip but I happen to never use sound on that system and so that is disabled. The problem is listed in syslog/dmesg by lines such as: kernel: irq 16: nobody cared (try booting with the "irqpoll" option) kernel: Disabling IRQ #16 Unfortunately, the HDDs and network interfaces also use that irq or "irg 17" (which can also be affected). Losing the irq will badly slow down your system and can cause data corruption for heavy use of the HDD. Use: lspci | grep -i ASM1083 to see if you have that chip and if so, what revision. To see if you have any irqpoll messages, use: grep -ia irqpoll /var/log/messages To list what devices use what interrupts, use either of: grep -ia ' irq ' /var/log/messages cat /proc/interrupts Note that there should no longer be any ASM1083 rev01 chips being supplied by now. (ASM1083 rev03 chips have been seen in products.) Hope that helps for that bit of obscurity! Martin -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
