On Friday 12 February 2010, Rafael J. Wysocki wrote: > On Friday 12 February 2010, Gary Hade wrote: ... > > There seems to be a problem. > > > > The first time I booted I was able to successfully hot-remove > > a PCIe card and then successfully hot-add it to a different slot. > > When I tried to hot-remove a PCI-X card that was also present > > during boot I saw that lingering blinking amber LED issue. > > > > After rebooting I tried the same thing but this time I did > > not see the lingering blinking amber LED after removing the > > PCI-X card but I did see it when removing the PCIe card. > > I then tried to hot-add the PCIe card to a different slot > > and noticed the below messages. > > > > I don't think I will be able to try to characterize this > > better or test any more patches until Monday. > > OK, thanks for testing. > > It seems we have a deadlock on pci_acpi_notify_mtx, but I'm yet to understand > the exact mechanism of it. In fact there are two problems in there. First, the bridge event notification calls handle_bridge_insertion() which attempts to install a PM notifier for the bridge and that deadlocks, because it tries to acquire the mutex recursively. Second, apparently, init_bridge_misc() may be called in the notification code path and it attempts to unregister the notifier and register it again, which can't be done with pci_acpi_notify_mtx held. I guess there are similar problems on the hot remove notification path. Anyway, I have a new version of the patch and I'm going to test it a bit over the weekend. Unfortunately, I don't have hardware with PCI hotplug capability, so I'll send you the new patch for testing on Monday, if you don't mind. Rafael -- 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
