Re: [PATCH v6 2/3] PCI/AER: Disable AER interrupt on suspend

From: Kai-Heng Feng
Date: Fri Jul 14 2023 - 04:16:08 EST


On Fri, May 12, 2023 at 8:01 AM Kai-Heng Feng
<kai.heng.feng@xxxxxxxxxxxxx> 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.
>
> 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>

A gentle ping...

> ---
> 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
>