[+cc Yinghai, Rajat] On Fri, Mar 7, 2014 at 7:33 AM, Andreas Noever <andreas.noever@xxxxxxxxx> wrote: > Hi, > > After upgrading to the latest RC I noticed that suprise removal > stopped working. Linux did not notice that the devices where gone. > Bisection points to > > 1f42db786b14a31bf807fc41ee5583a00c08fcb1 PCI: Enable INTx if BIOS left > them disabled > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1f42db786b14a31bf807fc41ee5583a00c08fcb1 > > It seems that the above patch is triggered on the bridge itself (!) > when a new device is added below it. At this point the hotplug driver > for the bridge has already enabled MSI. Reenabling INTX kills MSI and > prevents later suprise removal notifications. > > The following stacktrace is from a "echo 1 > rescan" on the bridge: > do_pci_enable_device+0x59/0x140 > pci_reenable_device+0x1f/0x30 > pci_assign_unassigned_bridge_resources+0x123/0x160 > pci_rescan_bus_bridge_resize+0x28/0x40 > dev_bus_rescan_store+0x85/0xa0 > dev_attr_store+0x18/0x30 > sysfs_kf_write+0x3d/0x50 > kernfs_fop_write+0xd2/0x140 > vfs_write+0xba/0x1e0 > SyS_write+0x49/0xa0 > system_call_fastpath+0x1a/0x1f > > Similarly for a hotplug event: > do_pci_enable_device+0x59/0x140 > pci_reenable_device+0x1f/0x30 > pci_assign_unassigned_bridge_resources+0x123/0x160 > pciehp_configure_device+0x90/0x160 > pciehp_enable_slot+0x163/0x280 > pciehp_power_thread+0xb8/0xe0 > process_one_work+0x167/0x420 > worker_thread+0x121/0x3a0 > > In both cases DisINTx is turned off and the hotplug driver stops > reacting to events. Thanks a lot for noticing and bisecting this! I opened a bugzilla report at https://bugzilla.kernel.org/show_bug.cgi?id=71691 It seems like clearing DisINTx has some effect on MSI. I don't see anything in the spec that would suggest this (I'm looking at the PCIe r3.0 spec, sec 7.5.1.1). Can somebody point out a connection between DisINTx and MSI? If not, maybe we'll need some sort of quirk to deal with this. Andrea, can you attach a complete dmesg log and "lspci -vv" output to the bugzilla? Thanks again! 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
