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

diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
index a1819df6c190aaa33098bb7638d749ed9ec25b68..6776265c51e7183414bd8722dee76ba73060f6b6 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/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));