On 12/9/22 4:29 PM, 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: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> > > This is a v3 based on Mika's patch at > https://lore.kernel.org/r/20221207084105.84947-1-mika.westerberg@xxxxxxxxxxxxxxx > > I wouldn't normally kibbitz like this, but I'm hoping to squeeze this into > the v6.2 merge window. > > Changes from v2: > > * Test the device type in get_port_device_capability() instead of > pcie_init_service_irqs(). The benefits are to keep the device type > checking together (this is similar to the PME test), avoid enabling Bus > Mastering unnecessarily, avoid exposing the portdrv AER service in > sysfs, and preventing the AER service driver from binding to devices it > doesn't need to. > > drivers/pci/pcie/portdrv.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c > index a6c4225505d5..8b16e96ec15c 100644 > --- a/drivers/pci/pcie/portdrv.c > +++ b/drivers/pci/pcie/portdrv.c > @@ -232,7 +232,9 @@ static int get_port_device_capability(struct pci_dev *dev) > } > > #ifdef CONFIG_PCIEAER > - if (dev->aer_cap && pci_aer_available() && > + if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT || > + pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC) && > + dev->aer_cap && pci_aer_available() && > (pcie_ports_native || host->native_aer)) > services |= PCIE_PORT_SERVICE_AER; > #endif -- Sathyanarayanan Kuppuswamy Linux Kernel Developer
