[PATCH] drm/amd/display: Add NULL pointer checks in dm_force_atomic_commit()

[Srinivasan Shanmugam]

This commit updates the dm_force_atomic_commit function to replace the
usage of PTR_ERR_OR_ZERO with IS_ERR for checking error states after
retrieving the Connector (drm_atomic_get_connector_state), CRTC
(drm_atomic_get_crtc_state), and Plane (drm_atomic_get_plane_state)
states.

The function utilized PTR_ERR_OR_ZERO for error checking. However, this
approach is inappropriate in this context because the respective
functions do not return NULL; they return pointers that encode errors.

This change ensures that error pointers are properly checked using
IS_ERR before attempting to dereference.

Cc: Harry Wentland <harry.wentl...@amd.com>
Cc: Nicholas Kazlauskas <nicholas.kazlaus...@amd.com>
Cc: Tom Chung <chiahsuan.ch...@amd.com>
Cc: Roman Li <roman...@amd.com>
Cc: Alex Hung <alex.h...@amd.com>
Cc: Aurabindo Pillai <aurabindo.pil...@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmu...@amd.com>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c  | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

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 012ff8332dd2..4a31d99da505 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -10621,16 +10621,20 @@ static int dm_force_atomic_commit(struct 
drm_connector *connector)
         */
        conn_state = drm_atomic_get_connector_state(state, connector);
 
-       ret = PTR_ERR_OR_ZERO(conn_state);
-       if (ret)
+       /* Check for error in getting connector state */
+       if (IS_ERR(conn_state)) {
+               ret = PTR_ERR(conn_state);
                goto out;
+       }
 
        /* Attach crtc to drm_atomic_state*/
        crtc_state = drm_atomic_get_crtc_state(state, 
&disconnected_acrtc->base);
 
-       ret = PTR_ERR_OR_ZERO(crtc_state);
-       if (ret)
+       /* Check for error in getting crtc state */
+       if (IS_ERR(crtc_state)) {
+               ret = PTR_ERR(crtc_state);
                goto out;
+       }
 
        /* force a restore */
        crtc_state->mode_changed = true;
@@ -10638,9 +10642,11 @@ static int dm_force_atomic_commit(struct drm_connector 
*connector)
        /* Attach plane to drm_atomic_state */
        plane_state = drm_atomic_get_plane_state(state, plane);
 
-       ret = PTR_ERR_OR_ZERO(plane_state);
-       if (ret)
+       /* Check for error in getting plane state */
+       if (IS_ERR(plane_state)) {
+               ret = PTR_ERR(plane_state);
                goto out;
+       }
 
        /* Call commit internally with the state we just constructed */
        ret = drm_atomic_commit(state);
-- 
2.34.1