On Tue, Jul 18, 2023 at 7:17 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > [+cc Rafael] > > On Fri, May 12, 2023 at 08:00:13AM +0800, Kai-Heng Feng wrote: > > PCIe services that share an IRQ with PME, such as AER or DPC, may cause a > > spurious wakeup on system suspend. To prevent this, disable the AER interrupt > > notification during the system suspend process. > > I see that in this particular BZ dmesg log, PME, AER, and DPC do share > the same IRQ, but I don't think this is true in general. > > Root Ports usually use MSI or MSI-X. PME and hotplug events use the > Interrupt Message Number in the PCIe Capability, but AER uses the one > in the AER Root Error Status register, and DPC uses the one in the DPC > Capability register. Those potentially correspond to three distinct > MSI/MSI-X vectors. > > I think this probably has nothing to do with the IRQ being *shared*, > but just that putting the downstream component into D3cold, where the > link state is L3, may cause the upstream component to log and signal a > link-related error as the link goes completely down. That's quite likely a better explanation than my wording. Assuming AER IRQ and PME IRQ are not shared, does system get woken up by AER IRQ? > > I don't think D0-D3hot should be relevant here because in all those > states, the link should be active because the downstream config space > remains accessible. So I'm not sure if it's possible, but I wonder if > there's a more targeted place we could do this, e.g., in the path that > puts downstream devices in D3cold. Let me try to work on this. Kai-Heng > > > As Per PCIe Base Spec 5.0, section 5.2, titled "Link State Power Management", > > TLP and DLLP transmission are disabled for a Link in L2/L3 Ready (D3hot), L2 > > (D3cold with aux power) and L3 (D3cold) states. So disabling the AER > > notification during suspend and re-enabling them during the resume process > > should not affect the basic functionality. > > > > 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> > > --- > > v6: > > v5: > > - Wording. > > > > v4: > > v3: > > - No change. > > > > v2: > > - Only disable AER IRQ. > > - No more check on PME IRQ#. > > - Use helper. > > > > 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, > > }; > > > > -- > > 2.34.1 > >
