From 9e8637d974f7ba0074841e5dcc57f27d26de149f Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Sun, 23 Feb 2025 00:04:35 -0600 Subject: [PATCH] drm/amd/display: Restore correct backlight brightness after a GPU reset commit 5760388d9681ac743038b846b9082b9023969551 upstream. [Why] GPU reset will attempt to restore cached state, but brightness doesn't get restored. It will come back at 100% brightness, but userspace thinks it's the previous value. [How] When running resume sequence if GPU is in reset restore brightness to previous value. Acked-by: Wayne Lin Signed-off-by: Mario Limonciello Signed-off-by: Tom Chung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 5e19e2b57b6bb640d68dfc7991e1e182922cf867) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index bfa15d8959553..a128259b19adb 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -218,6 +218,10 @@ amd_get_format_info(const struct drm_mode_fb_cmd2 *cmd); static void handle_hpd_irq_helper(struct amdgpu_dm_connector *aconnector); +static void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm, + int bl_idx, + u32 user_brightness); + static bool is_timing_unchanged_for_freesync(struct drm_crtc_state *old_crtc_state, struct drm_crtc_state *new_crtc_state); @@ -2698,6 +2702,12 @@ static int dm_resume(void *handle) mutex_unlock(&dm->dc_lock); + /* set the backlight after a reset */ + for (i = 0; i < dm->num_of_edps; i++) { + if (dm->backlight_dev[i]) + amdgpu_dm_backlight_set_level(dm, i, dm->brightness[i]); + } + return 0; } /* Recreate dc_state - DC invalidates it when setting power state to S3. */ -- 2.47.3