On Fri, May 12, 2023 at 6:08 AM Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote: > > > > On 5/11/23 6:36 AM, Kai-Heng Feng wrote: > > PCIe service that shares IRQ with PME may cause spurious wakeup on > > system suspend. > > > > This is very similar to previous attempts to suspend AER and DPC [1], > > but this time disabling AER IRQ is to prevent immediate PME wakeup when > > AER shares the same IRQ line with PME. > > IMHO, you don't need to mention the previous submission reason. Sure, will remove it in next revision. > > > > > It's okay to disable AER because 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), hence we don't lose much here to disable AER IRQ during > > system suspend. > > May be something like below? > > 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. > > 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. I'll shamelessly use this in the commit message :) Kai-Heng > > > > > [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> > > --- > > 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, > > }; > > > > -- > Sathyanarayanan Kuppuswamy > Linux Kernel Developer
