drm/vc4: kms: Warn if clk_set_min_rate fails

We currently ignore the clk_set_min_rate return code assuming it would
succeed. However, it can fail if we ask for a rate higher than the
current maximum for example.

Since we can't fail in atomic_commit, at least warn on failure.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-3-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_kms.c

@@ -406,7 +406,7 @@ static void vc4_atomic_commit_tail(struct drm_atomic_state *state)
 		 * Do a temporary request on the core clock during the
 		 * modeset.
 		 */
-		clk_set_min_rate(hvs->core_clk, core_rate);
+		WARN_ON(clk_set_min_rate(hvs->core_clk, core_rate));
 	}
 
 	drm_atomic_helper_commit_modeset_disables(dev, state);
@@ -439,7 +439,7 @@ static void vc4_atomic_commit_tail(struct drm_atomic_state *state)
 		 * Request a clock rate based on the current HVS
 		 * requirements.
 		 */
-		clk_set_min_rate(hvs->core_clk, new_hvs_state->core_clock_rate);
+		WARN_ON(clk_set_min_rate(hvs->core_clk, new_hvs_state->core_clock_rate));
 
 		drm_dbg(dev, "Core clock actual rate: %lu Hz\n",
 			clk_get_rate(hvs->core_clk));