On 3/24/2025 10:37, gregkh@linuxfoundation.org wrote:

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x acbf16a6ae775b4db86f537448cc466288aa307e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025032441-constrain-eastbound-09d8@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

Hi,

Here is them missing dependency commit. Cherry-picking this first will let the fix apply cleanly on 6.6.y:

commit bfeefe6ea5f1 ("drm/amd/display: should support dmub hw lock on Replay")

Thanks,

------------------ original commit in Linus's tree ------------------

From acbf16a6ae775b4db86f537448cc466288aa307e Mon Sep 17 00:00:00 2001 From: Mario Limonciello mario.limonciello@amd.com Date: Fri, 7 Mar 2025 15:55:20 -0600 Subject: [PATCH] drm/amd/display: Use HW lock mgr for PSR1 when only one eDP

[WHY] DMUB locking is important to make sure that registers aren't accessed while in PSR. Previously it was enabled but caused a deadlock in situations with multiple eDP panels.

[HOW] Detect if multiple eDP panels are in use to decide whether to use lock. Refactor the function so that the first check is for PSR-SU and then replay is in use to prevent having to look up number of eDP panels for those configurations.

Fixes: f245b400a223 ("Revert "drm/amd/display: Use HW lock mgr for PSR1"") Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3965 Reviewed-by: ChiaHsuan Chung chiahsuan.chung@amd.com Signed-off-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Alex Hung alex.hung@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com (cherry picked from commit ed569e1279a3045d6b974226c814e071fa0193a6) Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_hw_lock_mgr.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_hw_lock_mgr.c index bf636b28e3e1..6e2fce329d73 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dmub_hw_lock_mgr.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_hw_lock_mgr.c @@ -69,5 +69,16 @@ bool should_use_dmub_lock(struct dc_link *link) if (link->replay_settings.replay_feature_enabled) return true;

• /* only use HW lock for PSR1 on single eDP */
• if (link->psr_settings.psr_version == DC_PSR_VERSION_1) {

• struct dc_link *edp_links[MAX_NUM_EDP];
  

• int edp_num;
  

• dc_get_edp_links(link->dc, edp_links, &edp_num);
  

• if (edp_num == 1)
  

• 	return true;
  

• }
• return false; }