From: Alex Hung <alex.hung@amd.com>
Date: Fri, 20 Sep 2024 22:02:05 +0000 (-0600)
Subject: drm/amd/display: Check returns from drm_dp_dpcd_write
X-Git-Tag: v6.13-rc1~122^2~15^2~80
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=204f55736eb36b530cbcd6959477b44ed87a2213;p=thirdparty%2Fkernel%2Flinux.git

drm/amd/display: Check returns from drm_dp_dpcd_write

[WHAT & HOW]
drm_dp_dpcd_write() returns negative error on failure and thus returned
values need to be checked.

This fixes 3 UNUSED_VALUE issues reported by Coverity.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index 6923184a65363..8eaf292bc4eb1 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -643,6 +643,8 @@ static bool execute_synaptics_rc_command(struct drm_dp_aux *aux,
 		// write rc data
 		memmove(rc_data, data, length);
 		ret = drm_dp_dpcd_write(aux, SYNAPTICS_RC_DATA, rc_data, sizeof(rc_data));
+		if (ret < 0)
+			goto err;
 	}
 
 	// write rc offset
@@ -651,20 +653,21 @@ static bool execute_synaptics_rc_command(struct drm_dp_aux *aux,
 	rc_offset[2] = (unsigned char) (offset >> 16) & 0xFF;
 	rc_offset[3] = (unsigned char) (offset >> 24) & 0xFF;
 	ret = drm_dp_dpcd_write(aux, SYNAPTICS_RC_OFFSET, rc_offset, sizeof(rc_offset));
+	if (ret < 0)
+		goto err;
 
 	// write rc length
 	rc_length[0] = (unsigned char) length & 0xFF;
 	rc_length[1] = (unsigned char) (length >> 8) & 0xFF;
 	ret = drm_dp_dpcd_write(aux, SYNAPTICS_RC_LENGTH, rc_length, sizeof(rc_length));
+	if (ret < 0)
+		goto err;
 
 	// write rc cmd
 	rc_cmd = cmd | 0x80;
 	ret = drm_dp_dpcd_write(aux, SYNAPTICS_RC_COMMAND, &rc_cmd, sizeof(rc_cmd));
-
-	if (ret < 0) {
-		DRM_ERROR("%s: write cmd ..., err = %d\n",  __func__, ret);
-		return false;
-	}
+	if (ret < 0)
+		goto err;
 
 	// poll until active is 0
 	for (i = 0; i < 10; i++) {
@@ -687,6 +690,10 @@ static bool execute_synaptics_rc_command(struct drm_dp_aux *aux,
 	drm_dbg_dp(aux->drm_dev, "success = %d\n", success);
 
 	return success;
+
+err:
+	DRM_ERROR("%s: write cmd ..., err = %d\n",  __func__, ret);
+	return false;
 }
 
 static void apply_synaptics_fifo_reset_wa(struct drm_dp_aux *aux)