On Tue, Apr 25, 2023 at 7:47 AM Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote: > > > > On 4/23/23 10:52 PM, Kai-Heng Feng wrote: > > PCIe service that shares IRQ with PME may cause spurious wakeup on > > system suspend. > > > > PCIe Base Spec 5.0, section 5.2 "Link State Power Management" states > > that TLP and DLLP transmission is disabled for a Link in L2/L3 Ready > > (D3hot), L2 (D3cold with aux power) and L3 (D3cold), so we don't lose > > much here to disable AER during system suspend. > > > > This is very similar to previous attempts to suspend AER and DPC [1], > > but with a different reason. > > > > [1] https://lore.kernel.org/linux-pci/20220408153159.106741-1-kai.heng.feng@xxxxxxxxxxxxx/ > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=216295 > > > > Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > > --- > > IIUC, you encounter AER errors during the suspend/resume process, which > results in AER IRQ. Because AER and PME share an IRQ, it is regarded as a > spurious wake-up IRQ. So to fix it, you want to disable AER reporting, > right? Yes. That's exactly what happened. > > It looks like it is harmless to disable the AER during the suspend/resume > path. But, I am wondering why we get these errors? Did you check what errors > you get during the suspend/resume path? Are these errors valid? I really don't know. I think it's similar to the reasoning in commit b07461a8e45b ("PCI/AER: Clear error status registers during enumeration and restore"): "AER errors might be recorded when powering-on devices. These errors can be ignored, ...". For this case, it happens when powering-off the device (D3cold) via turning off power resources. Kai-Heng > > > > drivers/pci/pcie/aer.c | 22 ++++++++++++++++++++++ > > 1 file changed, 22 insertions(+) > > > > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c > > index 1420e1f27105..9c07fdbeb52d 100644 > > --- a/drivers/pci/pcie/aer.c > > +++ b/drivers/pci/pcie/aer.c > > @@ -1356,6 +1356,26 @@ static int aer_probe(struct pcie_device *dev) > > return 0; > > } > > > > +static int aer_suspend(struct pcie_device *dev) > > +{ > > + struct aer_rpc *rpc = get_service_data(dev); > > + struct pci_dev *pdev = rpc->rpd; > > + > > + aer_disable_irq(pdev); > > + > > + return 0; > > +} > > + > > +static int aer_resume(struct pcie_device *dev) > > +{ > > + struct aer_rpc *rpc = get_service_data(dev); > > + struct pci_dev *pdev = rpc->rpd; > > + > > + aer_enable_irq(pdev); > > + > > + return 0; > > +} > > + > > /** > > * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP > > * @dev: pointer to Root Port, RCEC, or RCiEP > > @@ -1420,6 +1440,8 @@ static struct pcie_port_service_driver aerdriver = { > > .service = PCIE_PORT_SERVICE_AER, > > > > .probe = aer_probe, > > + .suspend = aer_suspend, > > + .resume = aer_resume, > > .remove = aer_remove, > > }; > > > > -- > Sathyanarayanan Kuppuswamy > Linux Kernel Developer
