Re: [PATCH v2 5/5] Documentation/arch/x86/amd-debugging: Add section about delay_suspend

[Ilpo Järvinen]

On Tue, 12 May 2026, Daniel Gibson wrote:

> On 11.05.26 14:49, Ilpo Järvinen wrote:
> > On Sat, 9 May 2026, Daniel Gibson wrote:
> > 
> >> must be updated with the actual commit IDs when they are merged
> > 
> > Please write a proper changelog text.
> > 
> > Unfortunately, I cannot know the commit ID in advance as it depends on the 
> > commit content itself (git object hashing works that way).
> 
> Yeah, I know - I already feared I'd have to submit this documentation
> later when the other stuff is merged, but thought I'd post it here
> anyway to maybe get feedback on the documentation text itself while its
> context is in the same email thread.

Lets do so you keep it part of the series, for now.

I try to remember to apply only the other patches and you resubmit the 
last one with the correct id once I've accepted the other patches (and I 
try to remember to not rebase past that point after that).

> >> Signed-off-by: Daniel Gibson <daniel@xxxxxxxxx>
> >> ---
> >>  Documentation/arch/x86/amd-debugging.rst | 25 ++++++++++++++++++++++++
> >>  1 file changed, 25 insertions(+)
> >>
> >> diff --git a/Documentation/arch/x86/amd-debugging.rst b/Documentation/arch/x86/amd-debugging.rst
> >> index 3176a1240fee..3af7799cca1a 100644
> >> --- a/Documentation/arch/x86/amd-debugging.rst
> >> +++ b/Documentation/arch/x86/amd-debugging.rst
> >> @@ -249,6 +249,31 @@ state entry.
> >>  
> >>  `commit 40b8c14936bd2 ("drm/amd/display: Disable unneeded hpd interrupts during dm_init") <https://git.kernel.org/torvalds/c/40b8c14936bd2>`_
> >>  
> >> +Keyboard and Lid Switch stop working after resume
> >> +-------------------------------------------------
> >> +On various variants of the Lenovo IdeaPad Slim 3 with Barcelo and Rembrandt CPUs
> >> +the lid switch and keyboard, or at least the Fn/Multimedia keys, stopped working
> >> +after resume, until the next reboot.
> >> +
> >> +This was caused by buggy firmware having timing problems, the EC needed some idle
> >> +time right before the CPU cores are suspended, or it got into an inconsistent state.
> >> +
> >> +For laptops that are known to be affected this workaround is enabled
> >> +automatically, to test this workaround on other machines you can set the
> >> +``delay_suspend`` parameter of the ``amd_pmc`` module.
> >> +
> >> +If you need to set the ``delay_suspend`` parameter to fix your machine, please
> >> +report this at platform-driver-x86@xxxxxxxxxxxxxxx for it to be added to the
> >> +list of devices that need this workaround, so in future kernel versions it's
> >> +enabled automatically.
> >> +
> >> +Note that the current workaround isn't perfect: The problems can still happen
> >> +if resume is triggered by a timer (wakealarm).
> >> +
> >> +`commit TODO ("platform/x86/amd/pmc: Delay suspend for some Lenovo Laptops") <https://git.kernel.org/torvalds/c/TODO>`_
> >> +
> >> +`commit TODO ("platform/x86/amd/pmc: Add delay_suspend module parameter") <https://git.kernel.org/torvalds/c/TODO>`_
> >> +
> >>  Runtime power consumption issues
> >>  ================================
> >>  
> >>
> > 
> 

-- 
 i.