drm/radeon: check for 0 count in speaker allocation and SAD code

commit b67ce39a upstream.

If there is no speaker allocation block or SAD block, bail
early.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=72283Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/radeon/dce6_afmt.c

@@ -132,7 +132,7 @@ void dce6_afmt_write_speaker_allocation(struct drm_encoder *encoder)
 	}
 
 	sad_count = drm_edid_to_speaker_allocation(radeon_connector->edid, &sadb);
-	if (sad_count < 0) {
+	if (sad_count <= 0) {
 		DRM_ERROR("Couldn't read Speaker Allocation Data Block: %d\n", sad_count);
 		return;
 	}
@@ -193,7 +193,7 @@ void dce6_afmt_write_sad_regs(struct drm_encoder *encoder)
 	}
 
 	sad_count = drm_edid_to_sad(radeon_connector->edid, &sads);
-	if (sad_count < 0) {
+	if (sad_count <= 0) {
 		DRM_ERROR("Couldn't read SADs: %d\n", sad_count);
 		return;
 	}

drivers/gpu/drm/radeon/evergreen_hdmi.c

@@ -81,7 +81,7 @@ static void dce4_afmt_write_speaker_allocation(struct drm_encoder *encoder)
 	}
 
 	sad_count = drm_edid_to_speaker_allocation(radeon_connector->edid, &sadb);
-	if (sad_count < 0) {
+	if (sad_count <= 0) {
 		DRM_ERROR("Couldn't read Speaker Allocation Data Block: %d\n", sad_count);
 		return;
 	}
@@ -134,7 +134,7 @@ static void evergreen_hdmi_write_sad_regs(struct drm_encoder *encoder)
 	}
 
 	sad_count = drm_edid_to_sad(radeon_connector->edid, &sads);
-	if (sad_count < 0) {
+	if (sad_count <= 0) {
 		DRM_ERROR("Couldn't read SADs: %d\n", sad_count);
 		return;
 	}