drm/vc4: tests: Add unit test suite for the PV muxing

The HVS to PixelValve muxing code is fairly error prone and has a bunch
of arbitrary constraints due to the hardware setup.

Let's create a test suite that makes sure that the possible combinations
work and the invalid ones don't.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-19-4615a663a84a@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/Makefile

@@ -29,7 +29,8 @@ vc4-$(CONFIG_DRM_VC4_KUNIT_TEST) += \
 	tests/vc4_mock.o \
 	tests/vc4_mock_crtc.o \
 	tests/vc4_mock_output.o \
-	tests/vc4_mock_plane.o
+	tests/vc4_mock_plane.o \
+	tests/vc4_test_pv_muxing.o
 
 vc4-$(CONFIG_DEBUG_FS) += vc4_debugfs.o
 

drivers/gpu/drm/vc4/tests/vc4_mock.h

@@ -53,8 +53,11 @@ struct vc4_dummy_output *vc4_dummy_output(struct kunit *test,
 struct vc4_dev *vc4_mock_device(struct kunit *test);
 struct vc4_dev *vc5_mock_device(struct kunit *test);
 
-int vc4_mock_atomic_add_output(struct kunit *test, struct drm_device *drm,
-			       enum vc4_encoder_type type,
-			       struct drm_atomic_state *state);
+int vc4_mock_atomic_add_output(struct kunit *test,
+			       struct drm_atomic_state *state,
+			       enum vc4_encoder_type type);
+int vc4_mock_atomic_del_output(struct kunit *test,
+			       struct drm_atomic_state *state,
+			       enum vc4_encoder_type type);
 
 #endif // VC4_MOCK_H_

drivers/gpu/drm/vc4/tests/vc4_mock_output.c

@@ -61,16 +61,17 @@ static const struct drm_display_mode default_mode = {
 	DRM_SIMPLE_MODE(640, 480, 64, 48)
 };
 
-int vc4_mock_atomic_add_output(struct kunit *test, struct drm_device *drm,
-			       enum vc4_encoder_type type,
-			       struct drm_atomic_state *state)
+int vc4_mock_atomic_add_output(struct kunit *test,
+			       struct drm_atomic_state *state,
+			       enum vc4_encoder_type type)
 {
+	struct drm_device *drm = state->dev;
+	struct drm_connector_state *conn_state;
+	struct drm_crtc_state *crtc_state;
 	struct vc4_dummy_output *output;
 	struct drm_connector *conn;
-	struct drm_connector_state *conn_state;
 	struct drm_encoder *encoder;
 	struct drm_crtc *crtc;
-	struct drm_crtc_state *crtc_state;
 	int ret;
 
 	encoder = vc4_find_encoder_by_type(drm, type);
@@ -97,3 +98,41 @@ int vc4_mock_atomic_add_output(struct kunit *test, struct drm_device *drm,
 
 	return 0;
 }
+
+int vc4_mock_atomic_del_output(struct kunit *test,
+			       struct drm_atomic_state *state,
+			       enum vc4_encoder_type type)
+{
+	struct drm_device *drm = state->dev;
+	struct drm_connector_state *conn_state;
+	struct drm_crtc_state *crtc_state;
+	struct vc4_dummy_output *output;
+	struct drm_connector *conn;
+	struct drm_encoder *encoder;
+	struct drm_crtc *crtc;
+	int ret;
+
+	encoder = vc4_find_encoder_by_type(drm, type);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, encoder);
+
+	crtc = vc4_find_crtc_for_encoder(test, drm, encoder);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc);
+
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc_state);
+
+	crtc_state->active = false;
+
+	ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	output = container_of(encoder, struct vc4_dummy_output, encoder.base);
+	conn = &output->connector;
+	conn_state = drm_atomic_get_connector_state(state, conn);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, conn_state);
+
+	ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	return 0;
+}

drivers/gpu/drm/vc4/tests/vc4_test_pv_muxing.c

+// SPDX-License-Identifier: GPL-2.0
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_atomic_uapi.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_kunit_helpers.h>
+#include <drm/drm_mode.h>
+#include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_plane.h>
+
+#include <kunit/test.h>
+
+#include "../vc4_drv.h"
+
+#include "vc4_mock.h"
+
+struct pv_muxing_priv {
+	struct vc4_dev *vc4;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_state *state;
+};
+
+static bool check_fifo_conflict(struct kunit *test,
+				const struct drm_atomic_state *state)
+{
+	struct vc4_hvs_state *hvs_state;
+	unsigned int used_fifos = 0;
+	unsigned int i;
+
+	hvs_state = vc4_hvs_get_new_global_state(state);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hvs_state);
+
+	for (i = 0; i < HVS_NUM_CHANNELS; i++) {
+		if (!hvs_state->fifo_state[i].in_use)
+			continue;
+
+		KUNIT_EXPECT_FALSE(test, used_fifos & BIT(i));
+		used_fifos |= BIT(i);
+	}
+
+	return true;
+}
+
+struct encoder_constraint {
+	enum vc4_encoder_type type;
+	unsigned int *channels;
+	size_t nchannels;
+};
+
+#define ENCODER_CONSTRAINT(_type, ...)					\
+	{								\
+		.type = _type,						\
+		.channels = (unsigned int[]) { __VA_ARGS__ },		\
+		.nchannels = sizeof((unsigned int[]) { __VA_ARGS__ }) /	\
+			     sizeof(unsigned int),			\
+	}
+
+static bool __check_encoder_constraints(const struct encoder_constraint *constraints,
+					size_t nconstraints,
+					enum vc4_encoder_type type,
+					unsigned int channel)
+{
+	unsigned int i;
+
+	for (i = 0; i < nconstraints; i++) {
+		const struct encoder_constraint *constraint = &constraints[i];
+		unsigned int j;
+
+		if (constraint->type != type)
+			continue;
+
+		for (j = 0; j < constraint->nchannels; j++) {
+			unsigned int _channel = constraint->channels[j];
+
+			if (channel != _channel)
+				continue;
+
+			return true;
+		}
+	}
+
+	return false;
+}
+
+static const struct encoder_constraint vc4_encoder_constraints[] = {
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_DPI, 0),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_DSI0, 0),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_HDMI0, 1),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_VEC, 1),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_TXP, 2),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_DSI1, 2),
+};
+
+static const struct encoder_constraint vc5_encoder_constraints[] = {
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_DPI, 0),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_DSI0, 0),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_VEC, 1),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_TXP, 0, 2),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_DSI1, 0, 1, 2),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_HDMI0, 0, 1, 2),
+	ENCODER_CONSTRAINT(VC4_ENCODER_TYPE_HDMI1, 0, 1, 2),
+};
+
+static bool check_vc4_encoder_constraints(enum vc4_encoder_type type, unsigned int channel)
+{
+	return __check_encoder_constraints(vc4_encoder_constraints,
+					   ARRAY_SIZE(vc4_encoder_constraints),
+					   type, channel);
+}
+
+static bool check_vc5_encoder_constraints(enum vc4_encoder_type type, unsigned int channel)
+{
+	return __check_encoder_constraints(vc5_encoder_constraints,
+					   ARRAY_SIZE(vc5_encoder_constraints),
+					   type, channel);
+}
+
+static struct vc4_crtc_state *
+get_vc4_crtc_state_for_encoder(struct kunit *test,
+			       const struct drm_atomic_state *state,
+			       enum vc4_encoder_type type)
+{
+	struct drm_device *drm = state->dev;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_encoder *encoder;
+	struct drm_crtc *crtc;
+
+	encoder = vc4_find_encoder_by_type(drm, type);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, encoder);
+
+	crtc = vc4_find_crtc_for_encoder(test, drm, encoder);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, crtc);
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+	if (!new_crtc_state)
+		return NULL;
+
+	return to_vc4_crtc_state(new_crtc_state);
+}
+
+static bool check_channel_for_encoder(struct kunit *test,
+				      const struct drm_atomic_state *state,
+				      enum vc4_encoder_type type,
+				      bool (*check_fn)(enum vc4_encoder_type type, unsigned int channel))
+{
+	struct vc4_crtc_state *new_vc4_crtc_state;
+	struct vc4_hvs_state *new_hvs_state;
+	unsigned int channel;
+
+	new_hvs_state = vc4_hvs_get_new_global_state(state);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_hvs_state);
+
+	new_vc4_crtc_state = get_vc4_crtc_state_for_encoder(test, state, type);
+	KUNIT_ASSERT_NOT_NULL(test, new_vc4_crtc_state);
+
+	channel = new_vc4_crtc_state->assigned_channel;
+	KUNIT_EXPECT_NE(test, channel, VC4_HVS_CHANNEL_DISABLED);
+
+	KUNIT_EXPECT_TRUE(test, new_hvs_state->fifo_state[channel].in_use);
+
+	KUNIT_EXPECT_TRUE(test, check_fn(type, channel));
+
+	return true;
+}
+
+struct pv_muxing_param {
+	const char *name;
+	struct vc4_dev *(*mock_fn)(struct kunit *test);
+	bool (*check_fn)(enum vc4_encoder_type type, unsigned int channel);
+	enum vc4_encoder_type *encoders;
+	size_t nencoders;
+};
+
+static void vc4_test_pv_muxing_desc(const struct pv_muxing_param *t, char *desc)
+{
+	strscpy(desc, t->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+#define PV_MUXING_TEST(_name, _mock_fn, _check_fn, ...)					\
+	{										\
+		.name = _name,								\
+		.mock_fn = &_mock_fn,							\
+		.check_fn = &_check_fn,							\
+		.encoders = (enum vc4_encoder_type[]) { __VA_ARGS__ },			\
+		.nencoders = sizeof((enum vc4_encoder_type[]) { __VA_ARGS__ }) /	\
+			     sizeof(enum vc4_encoder_type),				\
+	}
+
+#define VC4_PV_MUXING_TEST(_name, ...)		\
+	PV_MUXING_TEST(_name, vc4_mock_device, check_vc4_encoder_constraints, __VA_ARGS__)
+
+#define VC5_PV_MUXING_TEST(_name, ...)		\
+	PV_MUXING_TEST(_name, vc5_mock_device, check_vc5_encoder_constraints, __VA_ARGS__)
+
+static const struct pv_muxing_param vc4_test_pv_muxing_params[] = {
+	VC4_PV_MUXING_TEST("1 output: DSI0",
+			   VC4_ENCODER_TYPE_DSI0),
+	VC4_PV_MUXING_TEST("1 output: DPI",
+			   VC4_ENCODER_TYPE_DPI),
+	VC4_PV_MUXING_TEST("1 output: HDMI0",
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC4_PV_MUXING_TEST("1 output: VEC",
+			   VC4_ENCODER_TYPE_VEC),
+	VC4_PV_MUXING_TEST("1 output: DSI1",
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("1 output: TXP",
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("2 outputs: DSI0, HDMI0",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC4_PV_MUXING_TEST("2 outputs: DSI0, VEC",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC),
+	VC4_PV_MUXING_TEST("2 outputs: DSI0, DSI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("2 outputs: DSI0, TXP",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("2 outputs: DPI, HDMI0",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC4_PV_MUXING_TEST("2 outputs: DPI, VEC",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC),
+	VC4_PV_MUXING_TEST("2 outputs: DPI, DSI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("2 outputs: DPI, TXP",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("2 outputs: HDMI0, DSI1",
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("2 outputs: HDMI0, TXP",
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("2 outputs: VEC, DSI1",
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("2 outputs: VEC, TXP",
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("3 outputs: DSI0, HDMI0, DSI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("3 outputs: DSI0, HDMI0, TXP",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("3 outputs: DSI0, VEC, DSI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("3 outputs: DSI0, VEC, TXP",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("3 outputs: DPI, HDMI0, DSI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("3 outputs: DPI, HDMI0, TXP",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("3 outputs: DPI, VEC, DSI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("3 outputs: DPI, VEC, TXP",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP),
+};
+
+KUNIT_ARRAY_PARAM(vc4_test_pv_muxing,
+		  vc4_test_pv_muxing_params,
+		  vc4_test_pv_muxing_desc);
+
+static const struct pv_muxing_param vc4_test_pv_muxing_invalid_params[] = {
+	VC4_PV_MUXING_TEST("DPI/DSI0 Conflict",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_DSI0),
+	VC4_PV_MUXING_TEST("TXP/DSI1 Conflict",
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC4_PV_MUXING_TEST("HDMI0/VEC Conflict",
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_VEC),
+	VC4_PV_MUXING_TEST("More than 3 outputs: DSI0, HDMI0, DSI1, TXP",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, DSI1, TXP",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("More than 3 outputs: DPI, HDMI0, DSI1, TXP",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_TXP),
+	VC4_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, DSI1, TXP",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_TXP),
+};
+
+KUNIT_ARRAY_PARAM(vc4_test_pv_muxing_invalid,
+		  vc4_test_pv_muxing_invalid_params,
+		  vc4_test_pv_muxing_desc);
+
+static const struct pv_muxing_param vc5_test_pv_muxing_params[] = {
+	VC5_PV_MUXING_TEST("1 output: DPI",
+			   VC4_ENCODER_TYPE_DPI),
+	VC5_PV_MUXING_TEST("1 output: DSI0",
+			   VC4_ENCODER_TYPE_DSI0),
+	VC5_PV_MUXING_TEST("1 output: DSI1",
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("1 output: HDMI0",
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("1 output: HDMI1",
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("1 output: VEC",
+			   VC4_ENCODER_TYPE_VEC),
+	VC5_PV_MUXING_TEST("2 outputs: DPI, DSI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("2 outputs: DPI, HDMI0",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("2 outputs: DPI, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("2 outputs: DPI, TXP",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_TXP),
+	VC5_PV_MUXING_TEST("2 outputs: DPI, VEC",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC),
+	VC5_PV_MUXING_TEST("2 outputs: DPI, DSI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("2 outputs: DSI0, DSI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("2 outputs: DSI0, HDMI0",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("2 outputs: DSI0, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("2 outputs: DSI0, TXP",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_TXP),
+	VC5_PV_MUXING_TEST("2 outputs: DSI0, VEC",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC),
+	VC5_PV_MUXING_TEST("2 outputs: DSI0, DSI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("2 outputs: DSI1, VEC",
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_VEC),
+	VC5_PV_MUXING_TEST("2 outputs: DSI1, TXP",
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_TXP),
+	VC5_PV_MUXING_TEST("2 outputs: DSI1, HDMI0",
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("2 outputs: DSI1, HDMI1",
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("2 outputs: HDMI0, VEC",
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_VEC),
+	VC5_PV_MUXING_TEST("2 outputs: HDMI0, TXP",
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_TXP),
+	VC5_PV_MUXING_TEST("2 outputs: HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("2 outputs: HDMI1, VEC",
+			   VC4_ENCODER_TYPE_HDMI1,
+			   VC4_ENCODER_TYPE_VEC),
+	VC5_PV_MUXING_TEST("2 outputs: HDMI1, TXP",
+			   VC4_ENCODER_TYPE_HDMI1,
+			   VC4_ENCODER_TYPE_TXP),
+	VC5_PV_MUXING_TEST("2 outputs: TXP, VEC",
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_VEC),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, VEC, TXP",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, VEC, DSI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, VEC, HDMI0",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, VEC, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, TXP, DSI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, TXP, HDMI0",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, TXP, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, DSI1, HDMI0",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, DSI1, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("3 outputs: DPI, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, VEC, TXP",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, VEC, DSI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, VEC, HDMI0",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, VEC, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, TXP, DSI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, TXP, HDMI0",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, TXP, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, DSI1, HDMI0",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, DSI1, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("3 outputs: DSI0, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+};
+
+KUNIT_ARRAY_PARAM(vc5_test_pv_muxing,
+		  vc5_test_pv_muxing_params,
+		  vc4_test_pv_muxing_desc);
+
+static const struct pv_muxing_param vc5_test_pv_muxing_invalid_params[] = {
+	VC5_PV_MUXING_TEST("DPI/DSI0 Conflict",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_DSI0),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, TXP, DSI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, TXP, HDMI0",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, TXP, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, DSI1, HDMI0",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, DSI1, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, TXP, DSI1, HDMI0",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, TXP, DSI1, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, TXP, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, DSI1, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, TXP, DSI1, HDMI0",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, TXP, DSI1, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, TXP, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, DSI1, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, TXP, DSI1, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, TXP, DSI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, TXP, HDMI0",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, TXP, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, DSI1, HDMI0",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, DSI1, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, TXP, DSI1, HDMI0",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, TXP, DSI1, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, TXP, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, DSI1, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, TXP, DSI1, HDMI0",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, TXP, DSI1, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, TXP, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, DSI1, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, TXP, DSI1, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: VEC, TXP, DSI1, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DPI, VEC, TXP, DSI1, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DPI,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+	VC5_PV_MUXING_TEST("More than 3 outputs: DSI0, VEC, TXP, DSI1, HDMI0, HDMI1",
+			   VC4_ENCODER_TYPE_DSI0,
+			   VC4_ENCODER_TYPE_VEC,
+			   VC4_ENCODER_TYPE_TXP,
+			   VC4_ENCODER_TYPE_DSI1,
+			   VC4_ENCODER_TYPE_HDMI0,
+			   VC4_ENCODER_TYPE_HDMI1),
+};
+
+KUNIT_ARRAY_PARAM(vc5_test_pv_muxing_invalid,
+		  vc5_test_pv_muxing_invalid_params,
+		  vc4_test_pv_muxing_desc);
+
+static void drm_vc4_test_pv_muxing(struct kunit *test)
+{
+	const struct pv_muxing_param *params = test->param_value;
+	const struct pv_muxing_priv *priv = test->priv;
+	struct drm_atomic_state *state = priv->state;
+	unsigned int i;
+	int ret;
+
+	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);
+		KUNIT_ASSERT_EQ(test, ret, 0);
+	}
+
+	ret = drm_atomic_check_only(state);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_TRUE(test,
+			  check_fifo_conflict(test, state));
+
+	for (i = 0; i < params->nencoders; i++) {
+		enum vc4_encoder_type enc_type = params->encoders[i];
+
+		KUNIT_EXPECT_TRUE(test, check_channel_for_encoder(test, state, enc_type,
+								  params->check_fn));
+	}
+}
+
+static void drm_vc4_test_pv_muxing_invalid(struct kunit *test)
+{
+	const struct pv_muxing_param *params = test->param_value;
+	const struct pv_muxing_priv *priv = test->priv;
+	struct drm_atomic_state *state = priv->state;
+	unsigned int i;
+	int ret;
+
+	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);
+		KUNIT_ASSERT_EQ(test, ret, 0);
+	}
+
+	ret = drm_atomic_check_only(state);
+	KUNIT_EXPECT_LT(test, ret, 0);
+}
+
+static int vc4_pv_muxing_test_init(struct kunit *test)
+{
+	const struct pv_muxing_param *params = test->param_value;
+	struct drm_atomic_state *state;
+	struct pv_muxing_priv *priv;
+	struct drm_device *drm;
+	struct vc4_dev *vc4;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, priv);
+	test->priv = priv;
+
+	vc4 = params->mock_fn(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vc4);
+	priv->vc4 = vc4;
+
+	drm_modeset_acquire_init(&priv->ctx, 0);
+
+	drm = &vc4->base;
+	state = drm_atomic_state_alloc(drm);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	state->acquire_ctx = &priv->ctx;
+
+	priv->state = state;
+
+	return 0;
+}
+
+static void vc4_pv_muxing_test_exit(struct kunit *test)
+{
+	struct pv_muxing_priv *priv = test->priv;
+	struct vc4_dev *vc4 = priv->vc4;
+	struct drm_device *drm = &vc4->base;
+	struct drm_atomic_state *state = priv->state;
+
+	drm_atomic_state_put(state);
+	drm_modeset_drop_locks(&priv->ctx);
+	drm_modeset_acquire_fini(&priv->ctx);
+	drm_dev_unregister(drm);
+	drm_kunit_helper_free_device(test, vc4->dev);
+}
+
+static struct kunit_case vc4_pv_muxing_tests[] = {
+	KUNIT_CASE_PARAM(drm_vc4_test_pv_muxing,
+			 vc4_test_pv_muxing_gen_params),
+	KUNIT_CASE_PARAM(drm_vc4_test_pv_muxing_invalid,
+			 vc4_test_pv_muxing_invalid_gen_params),
+	{}
+};
+
+static struct kunit_suite vc4_pv_muxing_test_suite = {
+	.name = "vc4-pv-muxing-combinations",
+	.init = vc4_pv_muxing_test_init,
+	.exit = vc4_pv_muxing_test_exit,
+	.test_cases = vc4_pv_muxing_tests,
+};
+
+static struct kunit_case vc5_pv_muxing_tests[] = {
+	KUNIT_CASE_PARAM(drm_vc4_test_pv_muxing,
+			 vc5_test_pv_muxing_gen_params),
+	KUNIT_CASE_PARAM(drm_vc4_test_pv_muxing_invalid,
+			 vc5_test_pv_muxing_invalid_gen_params),
+	{}
+};
+
+static struct kunit_suite vc5_pv_muxing_test_suite = {
+	.name = "vc5-pv-muxing-combinations",
+	.init = vc4_pv_muxing_test_init,
+	.exit = vc4_pv_muxing_test_exit,
+	.test_cases = vc5_pv_muxing_tests,
+};
+
+/* See
+ * https://lore.kernel.org/all/3e113525-aa89-b1e2-56b7-ca55bd41d057@samsung.com/
+ * and
+ * https://lore.kernel.org/dri-devel/20200917121623.42023-1-maxime@cerno.tech/
+ */
+static void drm_test_vc5_pv_muxing_bugs_subsequent_crtc_enable(struct kunit *test)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_state *state;
+	struct vc4_crtc_state *new_vc4_crtc_state;
+	struct vc4_hvs_state *new_hvs_state;
+	unsigned int hdmi0_channel;
+	unsigned int hdmi1_channel;
+	struct drm_device *drm;
+	struct vc4_dev *vc4;
+	int ret;
+
+	vc4 = vc5_mock_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vc4);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+	drm = &vc4->base;
+	state = drm_atomic_state_alloc(drm);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	state->acquire_ctx = &ctx;
+
+	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI0);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = drm_atomic_check_only(state);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_hvs_state = vc4_hvs_get_new_global_state(state);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_hvs_state);
+
+	new_vc4_crtc_state = get_vc4_crtc_state_for_encoder(test, state,
+							    VC4_ENCODER_TYPE_HDMI0);
+	KUNIT_ASSERT_NOT_NULL(test, new_vc4_crtc_state);
+
+	hdmi0_channel = new_vc4_crtc_state->assigned_channel;
+	KUNIT_ASSERT_NE(test, hdmi0_channel, VC4_HVS_CHANNEL_DISABLED);
+	KUNIT_ASSERT_TRUE(test, new_hvs_state->fifo_state[hdmi0_channel].in_use);
+
+	ret = drm_atomic_helper_swap_state(state, false);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_atomic_state_put(state);
+
+	state = drm_atomic_state_alloc(drm);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	state->acquire_ctx = &ctx;
+
+	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI1);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = drm_atomic_check_only(state);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_hvs_state = vc4_hvs_get_new_global_state(state);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_hvs_state);
+
+	new_vc4_crtc_state = get_vc4_crtc_state_for_encoder(test, state,
+							    VC4_ENCODER_TYPE_HDMI1);
+	KUNIT_ASSERT_NOT_NULL(test, new_vc4_crtc_state);
+
+	hdmi1_channel = new_vc4_crtc_state->assigned_channel;
+	KUNIT_ASSERT_NE(test, hdmi1_channel, VC4_HVS_CHANNEL_DISABLED);
+	KUNIT_ASSERT_TRUE(test, new_hvs_state->fifo_state[hdmi1_channel].in_use);
+
+	KUNIT_EXPECT_NE(test, hdmi0_channel, hdmi1_channel);
+
+	drm_atomic_state_put(state);
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+	drm_dev_unregister(drm);
+	drm_kunit_helper_free_device(test, vc4->dev);
+}
+
+static void drm_test_vc5_pv_muxing_bugs_stable_fifo(struct kunit *test)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_state *state;
+	struct vc4_crtc_state *new_vc4_crtc_state;
+	struct vc4_hvs_state *new_hvs_state;
+	unsigned int old_hdmi0_channel;
+	unsigned int old_hdmi1_channel;
+	struct drm_device *drm;
+	struct vc4_dev *vc4;
+	int ret;
+
+	vc4 = vc5_mock_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vc4);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+	drm = &vc4->base;
+	state = drm_atomic_state_alloc(drm);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	state->acquire_ctx = &ctx;
+
+	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI0);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI1);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = drm_atomic_check_only(state);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_hvs_state = vc4_hvs_get_new_global_state(state);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_hvs_state);
+
+	new_vc4_crtc_state = get_vc4_crtc_state_for_encoder(test, state,
+							    VC4_ENCODER_TYPE_HDMI0);
+	KUNIT_ASSERT_NOT_NULL(test, new_vc4_crtc_state);
+
+	old_hdmi0_channel = new_vc4_crtc_state->assigned_channel;
+	KUNIT_ASSERT_NE(test, old_hdmi0_channel, VC4_HVS_CHANNEL_DISABLED);
+	KUNIT_ASSERT_TRUE(test, new_hvs_state->fifo_state[old_hdmi0_channel].in_use);
+
+	new_vc4_crtc_state = get_vc4_crtc_state_for_encoder(test, state,
+							    VC4_ENCODER_TYPE_HDMI1);
+	KUNIT_ASSERT_NOT_NULL(test, new_vc4_crtc_state);
+
+	old_hdmi1_channel = new_vc4_crtc_state->assigned_channel;
+	KUNIT_ASSERT_NE(test, old_hdmi1_channel, VC4_HVS_CHANNEL_DISABLED);
+	KUNIT_ASSERT_TRUE(test, new_hvs_state->fifo_state[old_hdmi1_channel].in_use);
+
+	ret = drm_atomic_helper_swap_state(state, false);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_atomic_state_put(state);
+
+	state = drm_atomic_state_alloc(drm);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	state->acquire_ctx = &ctx;
+
+	ret = vc4_mock_atomic_del_output(test, state, VC4_ENCODER_TYPE_HDMI0);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = drm_atomic_check_only(state);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_hvs_state = vc4_hvs_get_new_global_state(state);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, new_hvs_state);
+
+	new_vc4_crtc_state = get_vc4_crtc_state_for_encoder(test, state,
+							    VC4_ENCODER_TYPE_HDMI1);
+
+	if (new_vc4_crtc_state) {
+		unsigned int hdmi1_channel;
+
+		hdmi1_channel = new_vc4_crtc_state->assigned_channel;
+		KUNIT_ASSERT_NE(test, hdmi1_channel, VC4_HVS_CHANNEL_DISABLED);
+		KUNIT_ASSERT_TRUE(test, new_hvs_state->fifo_state[hdmi1_channel].in_use);
+
+		KUNIT_EXPECT_EQ(test, old_hdmi1_channel, hdmi1_channel);
+	}
+
+	drm_atomic_state_put(state);
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+	drm_dev_unregister(drm);
+	drm_kunit_helper_free_device(test, vc4->dev);
+}
+
+static void
+drm_test_vc5_pv_muxing_bugs_subsequent_crtc_enable_too_many_crtc_state(struct kunit *test)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_state *state;
+	struct vc4_crtc_state *new_vc4_crtc_state;
+	struct drm_device *drm;
+	struct vc4_dev *vc4;
+	int ret;
+
+	vc4 = vc5_mock_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vc4);
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+	drm = &vc4->base;
+	state = drm_atomic_state_alloc(drm);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	state->acquire_ctx = &ctx;
+
+	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI0);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = drm_atomic_check_only(state);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = drm_atomic_helper_swap_state(state, false);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_atomic_state_put(state);
+
+	state = drm_atomic_state_alloc(drm);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, state);
+
+	state->acquire_ctx = &ctx;
+
+	ret = vc4_mock_atomic_add_output(test, state, VC4_ENCODER_TYPE_HDMI1);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = drm_atomic_check_only(state);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	new_vc4_crtc_state = get_vc4_crtc_state_for_encoder(test, state,
+							    VC4_ENCODER_TYPE_HDMI0);
+	KUNIT_EXPECT_NULL(test, new_vc4_crtc_state);
+
+	drm_atomic_state_put(state);
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+	drm_dev_unregister(drm);
+	drm_kunit_helper_free_device(test, vc4->dev);
+}
+
+static struct kunit_case vc5_pv_muxing_bugs_tests[] = {
+	KUNIT_CASE(drm_test_vc5_pv_muxing_bugs_subsequent_crtc_enable),
+	KUNIT_CASE(drm_test_vc5_pv_muxing_bugs_subsequent_crtc_enable_too_many_crtc_state),
+	KUNIT_CASE(drm_test_vc5_pv_muxing_bugs_stable_fifo),
+	{}
+};
+
+static struct kunit_suite vc5_pv_muxing_bugs_test_suite = {
+	.name = "vc5-pv-muxing-bugs",
+	.test_cases = vc5_pv_muxing_bugs_tests,
+};
+
+kunit_test_suites(
+	&vc4_pv_muxing_test_suite,
+	&vc5_pv_muxing_test_suite,
+	&vc5_pv_muxing_bugs_test_suite
+);