Lukas, On Mon, Oct 5, 2020 at 3:13 AM Lukas Wunner <lukas@xxxxxxxxx> wrote: > > On Sat, Oct 03, 2020 at 03:55:12AM -0400, Ethan Zhao wrote: > > When root port has DPC capability and it is enabled, then triggered by > > errors, DPC DLLSC and PDC etc interrupts will be sent to DPC driver, pciehp > > drivers almost at the same time. > > Do the DLLSC and PDC events occur as a result of handling the error > or do they occur independently? They could happen independently if links were recovered then the card was removed. They could happen as a result of handling the errors the same time. So don't assume DLLSC and PDC all occur at the same time. > > If the latter, I don't see how we can tell whether the card in the > slot is still the same. If PDC happens, the card in the slot might not be the same. so hot-removal /hot -plugin handling follows the PDC event. > > If the former, holding the hotplug slot's reset_lock and doing something > along the lines of pciehp_reset_slot() (or calling it directly) might > solve the race. DPC reset is done by hardware, only AER calls pciehp_reset_slot() as recovery handling initiated by software. Thanks, Ethan > > Thanks, > > Lukas
