[PATCH v9 1/2] PCI/AER: Disable AER service on suspend

[Bjorn Helgaas <helgaas@kernel.org>]

From: Kai-Heng Feng <kai.heng.feng@canonical.com>

If the link is powered off during suspend, electrical noise may cause
errors that are logged via AER.  If the AER interrupt is enabled and shares
an IRQ with PME, that causes a spurious wakeup during suspend.

Disable the AER interrupt during suspend to prevent this.  Clear error
status before re-enabling IRQ interrupts during resume so we don't get an
interrupt for errors that occurred during the suspend/resume process.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=209149
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216295
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218090
Link: https://lore.kernel.org/r/20240416043225.1462548-2-kai.heng.feng@canonical.com
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
[bhelgaas: drop pci_ancestor_pr3_present() etc, commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/pci/pcie/aer.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index ac6293c24976..13b8586924ea 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1497,6 +1497,22 @@ 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);
+
+	aer_disable_rootport(rpc);
+	return 0;
+}
+
+static int aer_resume(struct pcie_device *dev)
+{
+	struct aer_rpc *rpc = get_service_data(dev);
+
+	aer_enable_rootport(rpc);
+	return 0;
+}
+
 /**
  * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
  * @dev: pointer to Root Port, RCEC, or RCiEP
@@ -1561,6 +1577,8 @@ 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