drm/amd/display: Update connector on DSC property change

[Why]
We want to trigger atomic check on connector when
DSC debugfs properties are changed. The previous
method was reverted because it accessed connector
properties unsafely and would also heavily
impact performance.

[How]
Add a flag for forcing DSC update in CRTC state
and add connector to the state if the flag is set.
Signed-off-by: Eryk Brol <eryk.brol@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -9120,6 +9120,7 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 	enum dc_status status;
 	int ret, i;
 	bool lock_and_validation_needed = false;
+	struct dm_crtc_state *dm_old_crtc_state;
 
 	trace_amdgpu_dm_atomic_check_begin(state);
 
@@ -9162,9 +9163,12 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 	}
 #endif
 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
+		dm_old_crtc_state = to_dm_crtc_state(old_crtc_state);
+
 		if (!drm_atomic_crtc_needs_modeset(new_crtc_state) &&
 		    !new_crtc_state->color_mgmt_changed &&
-		    old_crtc_state->vrr_enabled == new_crtc_state->vrr_enabled)
+		    old_crtc_state->vrr_enabled == new_crtc_state->vrr_enabled &&
+			dm_old_crtc_state->dsc_force_changed == false)
 			continue;
 
 		if (!new_crtc_state->enable)

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h

@@ -438,6 +438,7 @@ struct dm_crtc_state {
 	bool freesync_timing_changed;
 	bool freesync_vrr_info_changed;
 
+	bool dsc_force_changed;
 	bool vrr_supported;
 	struct mod_freesync_config freesync_config;
 	struct dc_info_packet vrr_infopacket;

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c

@@ -1253,6 +1253,10 @@ static ssize_t dp_dsc_clock_en_write(struct file *f, const char __user *buf,
 				     size_t size, loff_t *pos)
 {
 	struct amdgpu_dm_connector *aconnector = file_inode(f)->i_private;
+	struct drm_connector *connector = &aconnector->base;
+	struct drm_device *dev = connector->dev;
+	struct drm_crtc *crtc = NULL;
+	struct dm_crtc_state *dm_crtc_state = NULL;
 	struct pipe_ctx *pipe_ctx;
 	int i;
 	char *wr_buf = NULL;
@@ -1295,6 +1299,25 @@ static ssize_t dp_dsc_clock_en_write(struct file *f, const char __user *buf,
 	if (!pipe_ctx || !pipe_ctx->stream)
 		goto done;
 
+	// Get CRTC state
+	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+
+	if (connector->state == NULL)
+		goto unlock;
+
+	crtc = connector->state->crtc;
+	if (crtc == NULL)
+		goto unlock;
+
+	drm_modeset_lock(&crtc->mutex, NULL);
+	if (crtc->state == NULL)
+		goto unlock;
+
+	dm_crtc_state = to_dm_crtc_state(crtc->state);
+	if (dm_crtc_state->stream == NULL)
+		goto unlock;
+
 	if (param[0] == 1)
 		aconnector->dsc_settings.dsc_force_enable = DSC_CLK_FORCE_ENABLE;
 	else if (param[0] == 2)
@@ -1302,6 +1325,14 @@ static ssize_t dp_dsc_clock_en_write(struct file *f, const char __user *buf,
 	else
 		aconnector->dsc_settings.dsc_force_enable = DSC_CLK_FORCE_DEFAULT;
 
+	dm_crtc_state->dsc_force_changed = true;
+
+unlock:
+	if (crtc)
+		drm_modeset_unlock(&crtc->mutex);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+	mutex_unlock(&dev->mode_config.mutex);
+
 done:
 	kfree(wr_buf);
 	return size;
@@ -1408,6 +1439,10 @@ static ssize_t dp_dsc_slice_width_write(struct file *f, const char __user *buf,
 {
 	struct amdgpu_dm_connector *aconnector = file_inode(f)->i_private;
 	struct pipe_ctx *pipe_ctx;
+	struct drm_connector *connector = &aconnector->base;
+	struct drm_device *dev = connector->dev;
+	struct drm_crtc *crtc = NULL;
+	struct dm_crtc_state *dm_crtc_state = NULL;
 	int i;
 	char *wr_buf = NULL;
 	uint32_t wr_buf_size = 42;
@@ -1449,6 +1484,25 @@ static ssize_t dp_dsc_slice_width_write(struct file *f, const char __user *buf,
 	if (!pipe_ctx || !pipe_ctx->stream)
 		goto done;
 
+	// Safely get CRTC state
+	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+
+	if (connector->state == NULL)
+		goto unlock;
+
+	crtc = connector->state->crtc;
+	if (crtc == NULL)
+		goto unlock;
+
+	drm_modeset_lock(&crtc->mutex, NULL);
+	if (crtc->state == NULL)
+		goto unlock;
+
+	dm_crtc_state = to_dm_crtc_state(crtc->state);
+	if (dm_crtc_state->stream == NULL)
+		goto unlock;
+
 	if (param[0] > 0)
 		aconnector->dsc_settings.dsc_num_slices_h = DIV_ROUND_UP(
 					pipe_ctx->stream->timing.h_addressable,
@@ -1456,6 +1510,14 @@ static ssize_t dp_dsc_slice_width_write(struct file *f, const char __user *buf,
 	else
 		aconnector->dsc_settings.dsc_num_slices_h = 0;
 
+	dm_crtc_state->dsc_force_changed = true;
+
+unlock:
+	if (crtc)
+		drm_modeset_unlock(&crtc->mutex);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+	mutex_unlock(&dev->mode_config.mutex);
+
 done:
 	kfree(wr_buf);
 	return size;
@@ -1561,6 +1623,10 @@ static ssize_t dp_dsc_slice_height_write(struct file *f, const char __user *buf,
 				     size_t size, loff_t *pos)
 {
 	struct amdgpu_dm_connector *aconnector = file_inode(f)->i_private;
+	struct drm_connector *connector = &aconnector->base;
+	struct drm_device *dev = connector->dev;
+	struct drm_crtc *crtc = NULL;
+	struct dm_crtc_state *dm_crtc_state = NULL;
 	struct pipe_ctx *pipe_ctx;
 	int i;
 	char *wr_buf = NULL;
@@ -1603,6 +1669,25 @@ static ssize_t dp_dsc_slice_height_write(struct file *f, const char __user *buf,
 	if (!pipe_ctx || !pipe_ctx->stream)
 		goto done;
 
+	// Get CRTC state
+	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+
+	if (connector->state == NULL)
+		goto unlock;
+
+	crtc = connector->state->crtc;
+	if (crtc == NULL)
+		goto unlock;
+
+	drm_modeset_lock(&crtc->mutex, NULL);
+	if (crtc->state == NULL)
+		goto unlock;
+
+	dm_crtc_state = to_dm_crtc_state(crtc->state);
+	if (dm_crtc_state->stream == NULL)
+		goto unlock;
+
 	if (param[0] > 0)
 		aconnector->dsc_settings.dsc_num_slices_v = DIV_ROUND_UP(
 					pipe_ctx->stream->timing.v_addressable,
@@ -1610,6 +1695,14 @@ static ssize_t dp_dsc_slice_height_write(struct file *f, const char __user *buf,
 	else
 		aconnector->dsc_settings.dsc_num_slices_v = 0;
 
+	dm_crtc_state->dsc_force_changed = true;
+
+unlock:
+	if (crtc)
+		drm_modeset_unlock(&crtc->mutex);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+	mutex_unlock(&dev->mode_config.mutex);
+
 done:
 	kfree(wr_buf);
 	return size;
@@ -1708,6 +1801,10 @@ static ssize_t dp_dsc_bits_per_pixel_write(struct file *f, const char __user *bu
 				     size_t size, loff_t *pos)
 {
 	struct amdgpu_dm_connector *aconnector = file_inode(f)->i_private;
+	struct drm_connector *connector = &aconnector->base;
+	struct drm_device *dev = connector->dev;
+	struct drm_crtc *crtc = NULL;
+	struct dm_crtc_state *dm_crtc_state = NULL;
 	struct pipe_ctx *pipe_ctx;
 	int i;
 	char *wr_buf = NULL;
@@ -1750,8 +1847,35 @@ static ssize_t dp_dsc_bits_per_pixel_write(struct file *f, const char __user *bu
 	if (!pipe_ctx || !pipe_ctx->stream)
 		goto done;
 
+	// Get CRTC state
+	mutex_lock(&dev->mode_config.mutex);
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+
+	if (connector->state == NULL)
+		goto unlock;
+
+	crtc = connector->state->crtc;
+	if (crtc == NULL)
+		goto unlock;
+
+	drm_modeset_lock(&crtc->mutex, NULL);
+	if (crtc->state == NULL)
+		goto unlock;
+
+	dm_crtc_state = to_dm_crtc_state(crtc->state);
+	if (dm_crtc_state->stream == NULL)
+		goto unlock;
+
 	aconnector->dsc_settings.dsc_bits_per_pixel = param[0];
 
+	dm_crtc_state->dsc_force_changed = true;
+
+unlock:
+	if (crtc)
+		drm_modeset_unlock(&crtc->mutex);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+	mutex_unlock(&dev->mode_config.mutex);
+
 done:
 	kfree(wr_buf);
 	return size;