drm/amd/powerplay: Add SMU WMTABLE Validity Check for Renoir

[Why]
SMU watermark table (WMTABLE) validity check is missing on Renoir.
This validity check is very useful for checking whether
WMTABLE is updated successfully.

[How]
Add SMU watermark validity check.

Signed-off-by: Zhan Liu <[e-mail]>
Reviewed-by: Hersen Wu <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/powerplay/renoir_ppt.c

···
 	}
 
 	/* pass data to smu controller */
-	ret = smu_write_watermarks_table(smu);
+	if ((smu->watermarks_bitmap & WATERMARKS_EXIST) &&
+			!(smu->watermarks_bitmap & WATERMARKS_LOADED)) {
+		ret = smu_write_watermarks_table(smu);
+		if (ret) {
+			pr_err("Failed to update WMTABLE!");
+			return ret;
+		}
+		smu->watermarks_bitmap |= WATERMARKS_LOADED;
+	}
 
-	return ret;
+	return 0;
 }
 
 static int renoir_get_power_profile_mode(struct smu_context *smu,