From c36bc1d09b636e57b2f043956b9011a7fd66a593 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 commit 81f4d4ba509522596143fd5d7dc2fc3495296b0a upstream. [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 Signed-off-by: Greg Kroah-Hartman --- 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 f06c918f5a33a..b259439a32050 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4898,6 +4898,21 @@ 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