[PATCH v2 0/8] PCI/ASPM: Fix pci_enable_link_state*() APIs behavior

[Manivannan Sadhasivam via B4 Relay <devnull+manivannan.sadhasivam.oss.qualcomm.com@kernel.org>]

Hi,

This series fixes the behavior of the pci_enable_link_state() and
pci_enable_link_state_locked() APIs to be in symmetry with
pci_disable_link_state*() couterparts.

First 5 patches fixes and cleans up the ASPM code and the last 3 patches
modifies the atheros drivers to use the pci{enable/disable}_link_state() APIs
instead of modifying the LNKCTL register directly for enabling ASPM.

NOTE: The current callers of the pci_enable_link_state_locked() APIs (vmd and
pcie-qcom) drivers doesn't look like depending on the old behavior of the API. I
can atleast assure that for pcie-qcom. For VMD, it would be great if VMD folks
CCed could provide their review tags for patch 2/6.

Also in this version, I've included a patch from Ilpo (patch 1) that disables
ASPM forcefully even if BIOS/ACPI didn't grant us permission. More details are
in the patch description. I think this patch is needed anyway since the device
drivers are forcefully disabling it even if PCI core was skipping ASPM disable
previously.

Testing
=======

I've tested this series on Lenovo Thinkpad T14s with WCN7850 chipset (so that's
just ath12k driver). Rest of the drivers are compile tested only.

Merging Strategy
================

Even though there is no build dependency between PCI core and atheros patches,
there is a functional dependency. So I'd recommend creating an immutable branch
with PCI patches and merging that branch into both PCI and linux-wireless trees
and finally merging the atheros patches into linux-wireless tree.

If immutable branch seems like a hassle, then PCI core patches could get merged
for 6.18 and atheros patches can wait for 6.19.

- Mani

Changes in v2:

* Reworked the pcie_aspm_enabled() API to return the enabled states instead of
  bool and used it to save/restore the ASPM states in ath drivers.
* Added a patch from Ilpo to disable ASPM even if BIOS didn't grant permission
* Added the CONFIG_PCIEASPM dependency to ath{10/11/12}k drivers as they now
  depend on the ASPM APIs for stable operation.
* Rebased on top of v6.17-rc1

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
Ilpo Järvinen (1):
      PCI/ASPM: Always disable ASPM when driver requests it

Manivannan Sadhasivam (7):
      PCI/ASPM: Fix the behavior of pci_enable_link_state*() APIs
      PCI/ASPM: Transition the device to D0 (if required) inside pci_enable_link_state_locked() API
      PCI/ASPM: Improve the kernel-doc for pci_disable_link_state*() APIs
      PCI/ASPM: Return enabled ASPM states from pcie_aspm_enabled() API
      wifi: ath12k: Use pci_{enable/disable}_link_state() APIs to enable/disable ASPM states
      wifi: ath11k: Use pci_{enable/disable}_link_state() APIs to enable/disable ASPM states
      wifi: ath10k: Use pci_{enable/disable}_link_state() APIs to enable/disable ASPM states

 drivers/net/wireless/ath/ath10k/Kconfig |   2 +-
 drivers/net/wireless/ath/ath10k/pci.c   |  11 ++--
 drivers/net/wireless/ath/ath10k/pci.h   |   5 +-
 drivers/net/wireless/ath/ath11k/Kconfig |   2 +-
 drivers/net/wireless/ath/ath11k/pci.c   |  19 +-----
 drivers/net/wireless/ath/ath11k/pci.h   |   3 +-
 drivers/net/wireless/ath/ath12k/Kconfig |   2 +-
 drivers/net/wireless/ath/ath12k/pci.c   |  19 +-----
 drivers/net/wireless/ath/ath12k/pci.h   |   4 +-
 drivers/pci/controller/dwc/pcie-qcom.c  |   5 --
 drivers/pci/controller/vmd.c            |   5 --
 drivers/pci/pcie/aspm.c                 | 103 ++++++++++++++++++++++----------
 include/linux/pci.h                     |   4 +-
 13 files changed, 92 insertions(+), 92 deletions(-)
---
base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
change-id: 20250825-ath-aspm-fix-588f135c9fb9

Best regards,
-- 
Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>