Hi Lukas, Thanks for the quick reply! I like your solution and have confirmed it solves the first deadlock we see between the Hotplug interrupt and AER recovery. Thanks, Ian On 6/15/20 1:56 PM, Lukas Wunner wrote: > On Mon, Jun 15, 2020 at 09:32:49AM -0500, Ian May wrote: >> Currently when a hotplug interrupt and AER recovery triggers simultaneously >> the following deadlock can occur. >> >> Hotplug AER >> ---------------------------- --------------------------- >> device_lock(&dev->dev) down_write(&ctrl->reset_lock) >> down_read(&ctrl->reset_lock) device_lock(&dev->dev) >> >> This patch adds a reset_lock and reset_unlock hotplug_slot_op. >> This would allow the controller reset_lock/reset_unlock to be moved >> from pciehp_reset_slot to pci_slot_reset function allowing the controller >> reset_lock to be acquired before the device lock allowing for both hotplug >> and AER to grab the reset_lock and device lock in proper order. > I've posted a patch to address such issues on Mar 31, just haven't > gotten around to respin it with a proper commit message: > > https://lore.kernel.org/linux-pci/20200331130139.46oxbade6rcbaicb@xxxxxxxxx/ > > I've solved it by moving the reset lock into struct pci_slot. > I think that's simpler than adding two callbacks. > > Do you think the AER deadlock could be fixed based on my approach? > > Thanks, > > Lukas
