Hi Bjorn, On Fri, Dec 09, 2022 at 06:29:22PM -0600, Bjorn Helgaas wrote: > From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > > Previously portdrv allowed the AER service for any device with an AER > capability (assuming Linux had control of AER) even though the AER service > driver only attaches to Root Port and RCECs. > > Because get_port_device_capability() included AER for non-RP, non-RCEC > devices, we tried to initialize the AER IRQ even though these devices > don't generate AER interrupts. > > Intel DG1 and DG2 discrete graphics cards contain a switch leading to a > GPU. The switch supports AER but not MSI, so initializing an AER IRQ > failed, and portdrv failed to claim the switch port at all. The GPU itself > could be suspended, but the switch could not be put in a low-power state > because it had no driver. > > Don't allow the AER service on non-Root Port, non-Root Complex Event > Collector devices. This means we won't enable Bus Mastering if the device > doesn't require MSI, the AER service will not appear in sysfs, and the AER > service driver will not bind to the device. > > Link: https://lore.kernel.org/r/20221207084105.84947-1-mika.westerberg@xxxxxxxxxxxxxxx > Based-on-patch-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> I asked our GPU folks to try this out too. Hoping to get some results during the week.
