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| author | Bjorn Helgaas <bhelgaas@google.com> | 2023-04-07 12:19:46 -0500 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2023-04-07 17:39:53 -0500 |
| commit | 774820b362b07b903354470f9372d528b327a3e5 (patch) | |
| tree | 348d4d691903dc8f1bad690677b5641ffa8e40bc /drivers/pci/pcie/edr.c | |
| parent | c441b1e03da6c680a3e12da59c554f454f2ccf5e (diff) | |
| download | linux-stable-774820b362b07b903354470f9372d528b327a3e5.tar.gz linux-stable-774820b362b07b903354470f9372d528b327a3e5.tar.bz2 linux-stable-774820b362b07b903354470f9372d528b327a3e5.zip | |
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.
Link: https://lore.kernel.org/r/20230407215259.GA3825733@bhelgaas
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Diffstat (limited to 'drivers/pci/pcie/edr.c')
| -rw-r--r-- | drivers/pci/pcie/edr.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c index 87734e4c3c20..5f4914d313a1 100644 --- a/drivers/pci/pcie/edr.c +++ b/drivers/pci/pcie/edr.c @@ -151,9 +151,18 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data) if (event != ACPI_NOTIFY_DISCONNECT_RECOVER) return; + /* + * pdev is a Root Port or Downstream Port that is still present and + * has triggered a containment event, e.g., DPC, so its child + * devices have been disconnected (ACPI r6.5, 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"); |