drm/vc4: tests: Retry pv-muxing tests when EDEADLK

Some functions used by the HVS->PV muxing tests can return with EDEADLK,
meaning the entire sequence should be restarted. It's not a fatal error
and we should treat it as a recoverable error, and recover, instead of
failing the test like we currently do.

Fixes: 76ec18dc5afa ("drm/vc4: tests: Add unit test suite for the PV muxing")
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20250403-drm-vc4-kunit-failures-v2-4-e09195cc8840@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>

1 files changed, 112 insertions, 1 deletions

diff --git a/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c b/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c
index 52c04ef33206..d1f694029169 100644
--- a/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c
+++ b/drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c
@@ -687,16 +687,30 @@ static void drm_vc4_test_pv_muxing(struct kunit *test)
 
 	vc4 = priv->vc4;
 	drm = &vc4->base;
+
+retry:
 	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
 	for (i = 0; i < params->nencoders; i++) {
 		enum vc4_encoder_type enc_type = params->encoders[i];
 
 		ret = vc4_mock_atomic_add_output(test, state, enc_type);
+		if (ret == -EDEADLK) {
+			drm_atomic_state_clear(state);
+			ret = drm_modeset_backoff(&ctx);
+			if (!ret)
+				goto retry;
+		}
 		KUNIT_ASSERT_EQ(test, ret, 0);
 	}
 
 	ret = drm_atomic_check_only(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry;
+	}
 	KUNIT_EXPECT_EQ(test, ret, 0);
 
 	KUNIT_EXPECT_TRUE(test,
@@ -728,6 +742,8 @@ static void drm_vc4_test_pv_muxing_invalid(struct kunit *test)
 
 	vc4 = priv->vc4;
 	drm = &vc4->base;
+
+retry:
 	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
 
@@ -735,10 +751,22 @@ static void drm_vc4_test_pv_muxing_invalid(struct kunit *test)
 		enum vc4_encoder_type enc_type = params->encoders[i];
 
 		ret = vc4_mock_atomic_add_output(test, state, enc_type);
+		if (ret == -EDEADLK) {
+			drm_atomic_state_clear(state);
+			ret = drm_modeset_backoff(&ctx);
+			if (!ret)
+				goto retry;
+		}
 		KUNIT_ASSERT_EQ(test, ret, 0);
 	}
 
 	ret = drm_atomic_check_only(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry;
+	}
 	KUNIT_EXPECT_LT(test, ret, 0);
 
 	drm_modeset_drop_locks(&ctx);
@@ -813,13 +841,26 @@ static void drm_test_vc5_pv_muxing_bugs_subsequent_crtc_enable(struct kunit *tes
 	drm_modeset_acquire_init(&ctx, 0);
 
 	drm = &vc4->base;
+retry_first:
 	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
 
 	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI0);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_first;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	ret = drm_atomic_check_only(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_first;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	new_hvs_state = vc4_hvs_get_new_global_state(state);
@@ -836,13 +877,26 @@ static void drm_test_vc5_pv_muxing_bugs_subsequent_crtc_enable(struct kunit *tes
 	ret = drm_atomic_helper_swap_state(state, false);
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
+retry_second:
 	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
 
 	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI1);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_second;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	ret = drm_atomic_check_only(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_second;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	new_hvs_state = vc4_hvs_get_new_global_state(state);
@@ -887,16 +941,35 @@ static void drm_test_vc5_pv_muxing_bugs_stable_fifo(struct kunit *test)
 	drm_modeset_acquire_init(&ctx, 0);
 
 	drm = &vc4->base;
+retry_first:
 	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
 
 	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI0);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_first;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI1);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_first;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	ret = drm_atomic_check_only(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_first;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	new_hvs_state = vc4_hvs_get_new_global_state(state);
@@ -921,13 +994,26 @@ static void drm_test_vc5_pv_muxing_bugs_stable_fifo(struct kunit *test)
 	ret = drm_atomic_helper_swap_state(state, false);
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
+retry_second:
 	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
 
 	ret = vc4_mock_atomic_del_output(test, state, VC4_ENCODER_TYPE_HDMI0);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_second;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	ret = drm_atomic_check_only(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_second;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	new_hvs_state = vc4_hvs_get_new_global_state(state);
@@ -981,25 +1067,50 @@ drm_test_vc5_pv_muxing_bugs_subsequent_crtc_enable_too_many_crtc_state(struct ku
 	drm_modeset_acquire_init(&ctx, 0);
 
 	drm = &vc4->base;
+retry_first:
 	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
 
 	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI0);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_first;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	ret = drm_atomic_check_only(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_first;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
-
 	ret = drm_atomic_helper_swap_state(state, false);
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
+retry_second:
 	state = drm_kunit_helper_atomic_state_alloc(test, drm, &ctx);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
 
 	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI1);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_second;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	ret = drm_atomic_check_only(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry_second;
+	}
 	KUNIT_ASSERT_EQ(test, ret, 0);
 
 	new_vc4_crtc_state = get_vc4_crtc_state_for_encoder(test, state,