linux/drivers/pci/pcie
Lukas Wunner 53b54ad074 PCI/DPC: Await readiness of secondary bus after reset
pci_bridge_wait_for_secondary_bus() is called after a Secondary Bus
Reset, but not after a DPC-induced Hot Reset.

As a result, the delays prescribed by PCIe r6.0 sec 6.6.1 are not
observed and devices on the secondary bus may be accessed before
they're ready.

One affected device is Intel's Ponte Vecchio HPC GPU.  It comprises a
PCIe switch whose upstream port is not immediately ready after reset.
Because its config space is restored too early, it remains in
D0uninitialized, its subordinate devices remain inaccessible and DPC
recovery fails with messages such as:

  i915 0000:8c:00.0: can't change power state from D3cold to D0 (config space inaccessible)
  intel_vsec 0000:8e:00.1: can't change power state from D3cold to D0 (config space inaccessible)
  pcieport 0000:89:02.0: AER: device recovery failed

Fix it.

Link: https://lore.kernel.org/r/9f5ff00e1593d8d9a4b452398b98aa14d23fca11.1673769517.git.lukas@wunner.de
Tested-by: Ravi Kishore Koppuravuri <ravi.kishore.koppuravuri@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: stable@vger.kernel.org
2023-02-09 12:46:15 -06:00
..
aer_inject.c PCI/AER: Update aer-inject URL 2022-03-02 11:26:17 -06:00
aer.c PCI/AER: Add optional logging callback for correctable error 2022-12-03 13:40:56 -08:00
aspm.c PCI/ASPM: Correct LTR_L1.2_THRESHOLD computation 2022-10-05 12:12:02 -05:00
dpc.c PCI/DPC: Await readiness of secondary bus after reset 2023-02-09 12:46:15 -06:00
edr.c PCI/EDR: Log only ACPI_NOTIFY_DISCONNECT_RECOVER events 2020-04-24 18:33:29 -05:00
err.c PCI/ERR: Recognize disconnected devices in report_error_detected() 2022-06-08 15:08:40 -05:00
Kconfig PCI: pciehp: Enable by default if USB4 enabled 2022-11-15 09:25:21 -06:00
Makefile PCI/portdrv: Squash into portdrv.c 2022-10-24 14:57:30 -05:00
pme.c PCI/PME: Use PCI_POSSIBLE_ERROR() to check config reads 2021-11-18 14:13:18 -06:00
portdrv.c Merge branch 'pci/portdrv' 2022-12-10 10:36:34 -06:00
portdrv.h PCI/portdrv: Move private things to portdrv.c 2022-10-24 14:57:30 -05:00
ptm.c PCI/PTM: Reorder functions in logical order 2022-09-12 15:29:52 -05:00
rcec.c PCI/RCEC: Fix RCiEP device to RCEC association 2021-03-10 15:10:46 -06:00