[PATCH v2 0/6] PCI/DPC: Decide DPC ownership with host_bridge->native_dpc

[Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>]

This series makes host_bridge->native_dpc the single decider for whether
Linux uses DPC, as Bjorn asked during the review of "Simplify PCIe native
ownership".

  https://lore.kernel.org/r/20261001221408.GA2731929@bhelgaas

Today the DPC service binds on host_bridge->native_aer, AER availability
and "pcie_ports=dpc-native".  host_bridge->native_dpc is only consulted
by pci_dpc_recovered().  After this series, native_dpc is the end result
of everything that decides DPC ownership, and portdrv binds the DPC
service on it.

The series depends on:

  - Three patches from v15 of "Simplify PCIe native ownership", merged
    into pci/portdrv.  They fold "pcie_ports=native" and
    "pcie_ports=dpc-native" into the _OSC control mask, so native_dpc
    already reflects the command line.

    https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/log/?h=portdrv

  - Two DPC patches from Lukas's "Error reporting for AER-incapable
    devices", which are included here directly as patches 1-2.

    https://lore.kernel.org/r/ae05fe2df3a3182594c4a9638daba1c72cf40358.1790531238.git.lukas@wunner.de
    https://lore.kernel.org/r/2ce502e5caa57db01e0a7bbc781210b66b73bec8.1790531238.git.lukas@wunner.de

Patch 1 keeps the DPC driver from accessing a non-existent AER
capability.

Patch 2 drops the AER ownership check from dpc_probe(), so DPC also
works on ports without an AER capability.

Patch 3 removes CONFIG_PCIE_EDR, which was another knob in deciding
whether to request DPC control in _OSC.

Patch 4 stops requiring pci_aer_available() to bind the DPC service,
since the DPC driver does not depend on MSI or on the AER driver.

Patch 5 requests DPC control only together with AER control, as PCI
Firmware r3.3, sec 4.5.2.4, requires.

Patch 6 binds the DPC service on host_bridge->native_dpc and logs a
message when the OS assumes DPC control that _OSC did not grant.

Changes since v1:

  - Include Lukas's two DPC patches instead of depending on his series
    (Bjorn).

  - Add Rafael's Acked-by to "Request DPC control only together with AER
    control".

  - Refer to "PCI/DPC: Reinstate support for AER-incapable ports" instead
    of Lukas's series in the native_dpc binding patch.

v1: https://lore.kernel.org/r/20261007165840.1604136-1-sathyanarayanan.kuppuswamy@linux.intel.com

Kuppuswamy Sathyanarayanan (4):
  PCI/EDR: Remove CONFIG_PCIE_EDR
  PCI/portdrv: Don't require AER to bind DPC service
  PCI/ACPI: Request DPC control only together with AER control
  PCI/portdrv: Bind DPC service based on host_bridge->native_dpc

Lukas Wunner (2):
  PCI/DPC: Avoid access to non-existent AER capability
  PCI/DPC: Reinstate support for AER-incapable ports

 drivers/acpi/pci_root.c    | 26 +++++++++++++++++++++++---
 drivers/pci/pcie/Kconfig   |  9 ---------
 drivers/pci/pcie/Makefile  |  5 ++++-
 drivers/pci/pcie/dpc.c     | 31 +++++++++++++------------------
 drivers/pci/pcie/portdrv.c |  7 +------
 include/linux/pci-acpi.h   |  4 ++--
 6 files changed, 43 insertions(+), 39 deletions(-)


base-commit: 4fe37866b0d92cdc45b62954a76489a9d9f8bd73
-- 
2.43.0