Re: [PATCH 0/4] Add support for drivers to decide bridge D3 policy

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Thursday, October 26, 2023 7:06:13 PM CEST Mario Limonciello wrote:
> On 10/26/2023 12:04, Rafael J. Wysocki wrote:
> > On Wednesday, October 25, 2023 4:05:42 AM CEST Mario Limonciello wrote:
> >> The policy for whether PCI bridges are allowed to select D3 is dictated
> >> by empirical results that are enumerated into pci_bridge_d3_possible().
> >>
> >> In Windows this behaves differently in that Windows internal policy is
> >> not used for devices when a power engine plugin driver provided by the
> >> SOC vendor is installed.  This driver is used to decide the policy in
> >> those cases.
> >>
> >> This series implements a system that lets drivers register such a policy
> >> control as well. It isn't activated for any SOCs by default.
> >>
> >> This is heavily leveraged from the work in [1]
> >>
> >> [1] https://lore.kernel.org/platform-driver-x86/20230906184354.45846-1-mario.limonciello@amd.com/
> >>
> >> RFC v1->PATCH v1
> >>   * Simplify the logic, use pci_d3cold_enable()/pci_d3cold_disable() functions
> >>   * Roll https://lore.kernel.org/linux-pci/20231004144731.158342-1-mario.limonciello@amd.com/ into series
> >>   * Updates for some typos
> >>   * Re-order series.  Patches 1 and 2 can potentially apply to PCI tree, 3 and 4 to platform-x86 tree.
> >>
> >> Mario Limonciello (4):
> >>    PCI: Make d3cold_allowed sysfs attribute read only
> >>    PCI: Refresh root ports in pci_bridge_d3_update()
> >>    ACPI: x86: s2idle: Export symbol for fetching constraints for module
> >>      use
> >>    platform/x86/amd: pmc: Add support for using constraints to decide D3
> >>      policy
> >>
> >>   Documentation/ABI/testing/sysfs-bus-pci |  4 +-
> >>   drivers/acpi/x86/s2idle.c               |  1 +
> >>   drivers/pci/pci-acpi.c                  |  2 +-
> >>   drivers/pci/pci-sysfs.c                 | 14 +-----
> >>   drivers/pci/pci.c                       | 12 ++++--
> >>   drivers/platform/x86/amd/pmc/pmc.c      | 57 +++++++++++++++++++++++++
> >>   include/linux/pci.h                     |  1 -
> >>   7 files changed, 72 insertions(+), 19 deletions(-)
> > 
> > Any chance to CC this series to linux-pm and linux-acpi?
> > 
> > 
> > 
> > 
> 
> Sure if it needs to spin again I'll send it to those lists as well.
> 
> Here's a lore link for you for now though if you want to respond to the 
> other patches.
> 
> https://lore.kernel.org/platform-driver-x86/0cd6648d-21f1-445d-95f6-20f580bbcfd1@amd.com/T/

Thanks, but I'm not the only person on linux-acpi and linux-pm
that may be interested in these changes.

Also please note that the material is related to ACPI and PM, so
quite relevant for those lists.