mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-11-01 17:08:10 +00:00
Code Issues Releases Wiki Activity

PCI/EDR: Clear Device Status after EDR error recovery

Browse source 
[ Upstream commit c441b1e03d ]

During EDR recovery, the OS must clear error status of the port that
triggered DPC even if firmware retains control of DPC and AER (see the
implementation note in the PCI Firmware spec r3.3, sec 4.6.12).

Prior to 068c29a248 ("PCI/ERR: Clear PCIe Device Status errors only if
OS owns AER"), the port Device Status was cleared in this path:

  edr_handle_event
    dpc_process_error(dev)                 # "dev" triggered DPC
    pcie_do_recovery(dev, dpc_reset_link)
      dpc_reset_link                       # exit DPC
      pcie_clear_device_status(dev)        # clear Device Status

After 068c29a248, pcie_do_recovery() no longer clears Device Status when
firmware controls AER, so the error bit remains set even after recovery.

Per the "Downstream Port Containment configuration control" bit in the
returned _OSC Control Field (sec 4.5.1), the OS is allowed to clear error
status until it evaluates _OST, so clear Device Status in
edr_handle_event() if the error recovery was successful.

[bhelgaas: commit log]
Fixes: 068c29a248 ("PCI/ERR: Clear PCIe Device Status errors only if OS owns AER")
Link: https://lore.kernel.org/r/20230315235449.1279209-1-sathyanarayanan.kuppuswamy@linux.intel.com
Reported-by: Tsaur Erwin <erwin.tsaur@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kuppuswamy Sathyanarayanan 2023-03-15 16:54:49 -07:00 committed by Greg Kroah-Hartman
parent cc4f0e168a
commit 1a2a0d5b06
1 changed files with 1 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
drivers/pci/pcie/edr.c
View file

@ -193,6 +193,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
*/
if (estate == PCI_ERS_RESULT_RECOVERED) {
pci_dbg(edev, "DPC port successfully recovered\n");
pcie_clear_device_status(edev);
acpi_send_edr_status(pdev, edev, EDR_OST_SUCCESS);
} else {
pci_dbg(edev, "DPC port recovery failed\n");