From 81f4d4ba509522596143fd5d7dc2fc3495296b0a Mon Sep 17 00:00:00 2001 From: "Mario Limonciello (AMD)" Date: Mon, 3 Nov 2025 16:02:11 -0600 Subject: [PATCH] drm/amd/display: Don't change brightness for disabled connectors [WHY] When a laptop lid is closed the connector is disabled but userspace can still try to change brightness. This doesn't work because the panel is turned off. It will eventually time out, but there is a lot of stutter along the way. [How] Iterate all connectors to check whether the matching one for the backlight index is enabled. Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4675 Cc: Mario Limonciello Cc: Alex Deucher Reviewed-by: Ray Wu Signed-off-by: Mario Limonciello (AMD) Signed-off-by: Alex Hung Signed-off-by: Alex Deucher (cherry picked from commit f6eeab30323d1174a4cc022e769d248fe8241304) Cc: stable@vger.kernel.org --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 15 +++++++++++++++ 1 file changed, 15 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 2a7a491a62e00..7fe40bbba2658 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -5052,6 +5052,21 @@ static void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm, struct dc_link *link; u32 brightness; bool rc, reallow_idle = false; + struct drm_connector *connector; + + list_for_each_entry(connector, &dm->ddev->mode_config.connector_list, head) { + struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector); + + if (aconnector->bl_idx != bl_idx) + continue; + + /* if connector is off, save the brightness for next time it's on */ + if (!aconnector->base.encoder) { + dm->brightness[bl_idx] = user_brightness; + dm->actual_brightness[bl_idx] = 0; + return; + } + } amdgpu_dm_update_backlight_caps(dm, bl_idx); caps = &dm->backlight_caps[bl_idx]; -- 2.47.3