On Fri, Apr 07, 2023 at 04:51:44PM -0500, Bjorn Helgaas wrote:
> I'll post a follow-up patch to add a couple comments there,
> too.
Comments I propose:
PCI/EDR: Add edr_handle_event() comments
EDR documentation is a bit sketchy. Add a couple comments to
edr_handle_event() about the devices involved.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c
index 87734e4c3c20..135ddb53661c 100644
--- a/drivers/pci/pcie/edr.c
+++ b/drivers/pci/pcie/edr.c
@@ -151,9 +151,17 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
if (event != ACPI_NOTIFY_DISCONNECT_RECOVER)
return;
+ /*
+ * pdev itself is still present, but one or more of its child
+ * devices have been disconnected (ACPI v6.3, sec 5.6.6).
+ */
pci_info(pdev, "EDR event received\n");
- /* Locate the port which issued EDR event */
+ /*
+ * Locate the port that experienced the containment event. pdev
+ * may be that port or a parent of it (PCI Firmware r3.3, sec
+ * 4.6.13).
+ */
edev = acpi_dpc_port_get(pdev);
if (!edev) {
pci_err(pdev, "Firmware failed to locate DPC port\n");
