On Fri, Aug 09, 2019 at 12:28:43PM +0200, Lukas Wunner wrote: > A sysfs request to enable or disable a PCIe hotplug slot should not > return before it has been carried out. That is sought to be achieved > by waiting until the controller's "pending_events" have been cleared. > > However the IRQ thread pciehp_ist() clears the "pending_events" before > it acts on them. If pciehp_sysfs_enable_slot() / _disable_slot() happen > to check the "pending_events" after they have been cleared but while > pciehp_ist() is still running, the functions may return prematurely > with an incorrect return value. > > Fix by introducing an "ist_running" flag which must be false before a > sysfs request is allowed to return. Can you instead just call synchronize_irq(ctrl->pcie->irq) after the pending events is cleared?
