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 <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Ray Wu <ray.wu@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 c60b2a4f6a66144fbb92ea67c8f03c555b342fc8..020f5a4f646320816bfc3d71359541277880fd73 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -5125,6 +5125,21 @@ 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];