Re: [PATCH] PCI:ASPM: Remove pcie_aspm_pm_state_change()

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Apr 24, 2023 at 12:35:36PM -0600, Mark Hasemeyer wrote:
> > Odd, it does not apply cleanly, so how was this tested?  Can you please
> > send the tested backport that you have so we know to get it correct?
> 
> Sorry about that. I had to apply a trivial backport as
> `pci_set_low_power_state` does not exist in v5.15.  It was tested by using an
> RTC wake in combination with using the sysfs to trigger a suspend:
> ```
> echo +5 > /sys/class/rtc/rtc0/wakealarm && echo freeze > /sys/power/state
> ```
> 
> Patch below.
> ------------------------------------
> >From 5ca368f6918710bf491feee54e09a060de835d3f Mon Sep 17 00:00:00 2001
> From: Kai-Heng Feng <kai.heng.feng@canonical.com>
> Date: Mon, 11 Jul 2022 18:07:01 -0500
> Subject: [PATCH] PCI/ASPM: Remove pcie_aspm_pm_state_change()
> 
> pcie_aspm_pm_state_change() was introduced at the inception of PCIe ASPM
> code, but it can cause some issues. For instance, when ASPM config is
> changed via sysfs, those changes won't persist across power state change
> because pcie_aspm_pm_state_change() overwrites them.
> 
> Also, if the driver restores L1SS [1] after system resume, the restored
> state will also be overwritten by pcie_aspm_pm_state_change().
> 
> Remove pcie_aspm_pm_state_change().  If there's any hardware that really
> needs it to function, a quirk can be used instead.
> 
> [1] https://lore.kernel.org/linux-pci/20220201123536.12962-1-vidyas@nvidia.com/
> Link: https://lore.kernel.org/r/20220509073639.2048236-1-kai.heng.feng@canonical.com
> [bhelgaas: remove additional pcie_aspm_pm_state_change() call in
> pci_set_low_power_state(), added by
> 10aa5377fc8a ("PCI/PM: Split pci_raw_set_power_state()") and moved by
> 7957d201456f ("PCI/PM: Relocate pci_set_low_power_state()")]
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> Signed-off-by: Mark Hasemeyer <markhas@chromium.org>
> ---
>  drivers/pci/pci.c       |  3 ---
>  drivers/pci/pci.h       |  2 --
>  drivers/pci/pcie/aspm.c | 19 -------------------
>  3 files changed, 24 deletions(-)

What is the git commit id of this change in Linus's tree?

And can you send it as a stand-alone patch, not one that I have to
hand-edit out of an email to use?  Doing that does not scale at the rate
of change we currently deal with at all.

thanks,

greg k-h