Re: [PATCH 0/4] PCI/DPC: Decide DPC ownership with host_bridge->native_dpc

[Bjorn Helgaas]

On Wed, Oct 07, 2026 at 09:58:36AM -0700, Kuppuswamy Sathyanarayanan wrote:
> 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 applies on top of two others:
> 
>   - pci/portdrv, which has patches 1-3 of v15 of "Simplify PCIe native
>     ownership".  They fold "pcie_ports=native" and "pcie_ports=dpc-native"
>     into the _OSC control mask, so native_dpc already reflects the
>     command line.
> 
>     https://lore.kernel.org/r/20261002211828.1293177-1-sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx
> 
>   - Lukas's "Error reporting for AER-incapable devices".  It removes the
>     AER Capability requirement from the DPC driver.
> 
>     https://lore.kernel.org/r/cover.1790531238.git.lukas@xxxxxxxxx

My impression was that Lukas planned to tweak a couple things in that
series, e.g., https://lore.kernel.org/all/arltOHrdHdokyfC9@xxxxxxxxx

Does this actually depend on Lukas' series?  If so, can we include the
relevant patch here?

> Patch 1 removes CONFIG_PCIE_EDR, which was another knob in deciding
> whether to request DPC control in _OSC.
> 
> Patch 2 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 3 requests DPC control only together with AER control, as PCI
> Firmware r3.3, sec 4.5.2.4, requires.
> 
> Patch 4 binds the DPC service on host_bridge->native_dpc and logs a
> message when the OS assumes DPC control that _OSC did not grant.
> 
> 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
> 
>  drivers/acpi/pci_root.c    | 26 +++++++++++++++++++++++---
>  drivers/pci/pcie/Kconfig   |  9 ---------
>  drivers/pci/pcie/Makefile  |  5 ++++-
>  drivers/pci/pcie/dpc.c     |  5 +++--
>  drivers/pci/pcie/portdrv.c |  7 +------
>  include/linux/pci-acpi.h   |  4 ++--
>  6 files changed, 33 insertions(+), 23 deletions(-)
> 
> 
> base-commit: 4fe37866b0d92cdc45b62954a76489a9d9f8bd73
> prerequisite-patch-id: e0eafcb39f15c38f3acfa601dfce07a6f0832ce1
> prerequisite-patch-id: 83e8185612e785fad80790d4a0c20fa68ab12ce7
> prerequisite-patch-id: 8e9e2b06f55249ff57c7d7f43918ee82f79d1450
> prerequisite-patch-id: 78ad13a1c423c3ee50122237c4bd0fdedf2d1e00
> prerequisite-patch-id: 0c4b9d46eea86635c431382aef2bf576a3bb5691
> prerequisite-patch-id: 2d1a35309e750427352c6fe0d9bb62c4453c6252
> prerequisite-patch-id: c1ed9c8ac6123e0a65ae0d7ba3183dd46477edf7
> -- 
> 2.43.0
>