On Mon, Apr 29, 2013 at 10:19 AM, Jiang Liu <liuj97@xxxxxxxxx> wrote: > Hi Yinghai, > Reviewed-by: Jiang Liu <jiang.liu@xxxxxxxxxx> > Thanks! > > On 04/26/2013 09:46 AM, Yinghai Lu wrote: >> Gavin found that acpiphp does not handle hotplug anymore even after >> now we have acpiphp built-in preparing for v3.10. >> >> Bjorn analyzed bootlog, he found that >> acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5 >> ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-3e]) >> \_SB_.PCI0:_OSC invalid UUID >> acpiphp: Slot [1] registered >> acpiphp: Slot [1-1] registered >> acpi root: \_SB_.PCI0 notify handler is installed >> _handle_hotplug_event_root: Bus check notify on \_SB_.PCI0 >> _handle_hotplug_event_root: Bus check notify on \_SB_.PCI0 >> And that means: >> So we should be using acpiphp, which you do have built in statically, >> and it found a couple slots. And we did get two bus check notifies on >> \_SB_.PCI0, so we *should* be re-enumerating PCI bus 0000:00. But it >> looks like we're handling this as a host bridge hotplug event instead >> of a PCI device hotplug. My guess is that >> handle_root_bridge_insertion() does nothing because the PCI0 ACPI >> device already exists, though I would expect to see the "acpi device >> exists..." in your dmesg log if this were the case. >> >> Also according to Rafael and Bjorn, it is perfect fine that we >> should enumerate bus by sending event to root bridge after hotadd >> device to slots under that root bridge or children bridges. >> >> It turns out that it is regression caused by >> | commit 668192b678201d2fff27c6cc76bb003c1ec4a52a >> | Author: Yinghai Lu <yinghai@xxxxxxxxxx> >> | Date: Mon Jan 21 13:20:48 2013 -0800 >> | >> | PCI: acpiphp: Move host bridge hotplug to pci_root.c >> >> We should check slots when BUS_CHECK is sent to root bridge acpi handle. >> >> Restore the old behavoir by calling acpi_check_bridge and check_sub_bridge >> in acpiphp. >> >> Jiang Liu acctually have simimar patch but it forgets calling >> acpi_check_bridge() for system that have slots on root bus directly. >> That is still valid, as in QEMU we still have that slots on bus 0 at >> least. But my first version patch wrongly check if root bridge exists >> before check_sub_bridge for children bridges. >> >> -v2: Don't check bridge for acpi_walk_namespace with check_sub_bridges. >> also put back bridge reference. >> -v3: More changelog and etc. >> >> Reported-by: Gavin Guo <tuffkidtt@xxxxxxxxx> >> Tested-by: Gavin Guo <tuffkidtt@xxxxxxxxx> >> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> I added the Acked-by and Reviewed-by and opened https://bugzilla.kernel.org/show_bug.cgi?id=57961 just as a place to store the dmesg logs. I also backported it to v3.9 and added a CC: stable tag because I think v3.9 has the same issue. The backport is also attached to the bugzilla. I'll ask Linus to put this in v3.10. Thanks, Bjorn -- 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
