drm/amd/display: Fix BUG_ON during CRTC atomic check update

For cases where the CRTC is inactive (DPMS off), where a modeset is not
required, yet the CRTC is still in the atomic state, we should not
attempt to update anything on it.

Previously, we were relying on the modereset_required() helper to check
the above condition. However, the function returns false immediately if
a modeset is not required, ignoring the CRTC's enable/active state
flags. The correct way to filter is by looking at these flags instead.

Fixes: e277adc5a06c "drm/amd/display: Hookup color management functions"
Bugzilla: https://bugs.freedesktop.org/106194

Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Tested-by: Michel Dänzer <michel.daenzer@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 1dd1142..ad1ad33 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -4695,15 +4695,16 @@ next_crtc:
                 * We want to do dc stream updates that do not require a
                 * full modeset below.
                 */
-               if (!enable || !aconnector || modereset_required(new_crtc_state))
+               if (!(enable && aconnector && new_crtc_state->enable &&
+                     new_crtc_state->active))
                        continue;
                /*
                 * Given above conditions, the dc state cannot be NULL because:
-                * 1. We're attempting to enable a CRTC. Which has a...
-                * 2. Valid connector attached, and
-                * 3. User does not want to reset it (disable or mark inactive,
-                *    which can happen on a CRTC that's already disabled).
-                * => It currently exists.
+                * 1. We're in the process of enabling CRTCs (just been added
+                *    to the dc context, or already is on the context)
+                * 2. Has a valid connector attached, and
+                * 3. Is currently active and enabled.
+                * => The dc stream state currently exists.
                 */
                BUG_ON(dm_new_crtc_state->stream == NULL);