[PATCH v2 14/14] drm/amd/display: Trigger modesets on MST DSC connectors

[Lyude Paul]

This should definitely be implemented as an atomic helper in
drm_dp_mst_topology.c as well.

On Tue, 2019-08-20 at 15:12 -0400, David Francis wrote:
> Whenever a connector on an MST network is attached, detached, or
> undergoes a modeset, the DSC configs for each stream on that
> topology will be recalculated. This can change their required
> bandwidth, requiring a full reprogramming, as though a modeset
> was performed, even if that stream did not change timing.
> 
> Therefore, whenever a crtc has drm_atomic_crtc_needs_modeset,
> for each crtc that shares a MST topology with that stream and
> supports DSC, add that crtc (and all affected connectors and
> planes) to the atomic state and set mode_changed on its state
> 
> v2: Do this check only on Navi and before adding connectors
> and planes on modesetting crtcs
> 
> Cc: Leo Li <sunpeng.li at amd.com>
> Cc: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
> Signed-off-by: David Francis <David.Francis at amd.com>
> ---
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 74 +++++++++++++++++++
>  1 file changed, 74 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 145fd73025dc..e64f2a6eb71a 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -6475,7 +6475,70 @@ static int do_aquire_global_lock(struct drm_device
> *dev,
>  
>  	return ret < 0 ? ret : 0;
>  }
> +#ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
> +static int add_affected_mst_dsc_crtcs(struct drm_atomic_state *state,
> struct drm_crtc *crtc)
> +{
> +	struct drm_connector *connector;
> +	struct drm_connector_state *conn_state;
> +	struct drm_connector_list_iter conn_iter;
> +	struct drm_crtc_state *new_crtc_state;
> +	struct amdgpu_dm_connector *aconnector = NULL, *aconnector_to_add;
> +	int i, j;
> +	struct drm_crtc *crtcs_affected[AMDGPU_MAX_CRTCS] = { 0 };
> +
> +	for_each_new_connector_in_state(state, connector, conn_state, i) {
> +		if (conn_state->crtc != crtc)
> +			continue;
> +
> +		aconnector = to_amdgpu_dm_connector(connector);
> +		if (!aconnector->port)
> +			aconnector = NULL;
> +		else
> +			break;
> +	}
> +
> +	if (!aconnector)
> +		return 0;
> +
> +	i = 0;
> +	drm_connector_list_iter_begin(state->dev, &conn_iter);
> +	drm_for_each_connector_iter(connector, &conn_iter) {
> +		if (!connector->state || !connector->state->crtc)
> +			continue;
> +
> +		aconnector_to_add = to_amdgpu_dm_connector(connector);
> +		if (!aconnector_to_add->port)
> +			continue;
> +
> +		if (aconnector_to_add->port->mgr != aconnector->port->mgr)
> +			continue;
>  
> +		if (!aconnector_to_add->dc_sink)
> +			continue;
> +
> +		if (!aconnector_to_add->dc_sink-
> >sink_dsc_caps.dsc_dec_caps.is_dsc_supported)
> +			continue;
> +
> +		if (i >= AMDGPU_MAX_CRTCS)
> +			continue;
> +
> +		crtcs_affected[i] = connector->state->crtc;
> +		i++;
> +	}
> +	drm_connector_list_iter_end(&conn_iter);
> +
> +	for (j = 0; j < i; j++) {
> +		new_crtc_state = drm_atomic_get_crtc_state(state,
> crtcs_affected[j]);
> +		if (IS_ERR(new_crtc_state))
> +			return PTR_ERR(new_crtc_state);
> +
> +		new_crtc_state->mode_changed = true;
> +	}
> +
> +	return 0;
> +
> +}
> +#endif
>  static void get_freesync_config_for_crtc(
>  	struct dm_crtc_state *new_crtc_state,
>  	struct dm_connector_state *new_con_state)
> @@ -7160,6 +7223,17 @@ static int amdgpu_dm_atomic_check(struct drm_device
> *dev,
>  	if (ret)
>  		goto fail;
>  
> +#ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
> +	if (adev->asic_type >= CHIP_NAVI10) {
> +		for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state,
> new_crtc_state, i) {
> +			if (drm_atomic_crtc_needs_modeset(new_crtc_state)) {
> +				ret = add_affected_mst_dsc_crtcs(state, crtc);
> +				if (ret)
> +					goto fail;
> +			}
> +		}
> +	}
> +#endif
>  	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state,
> new_crtc_state, i) {
>  		if (!drm_atomic_crtc_needs_modeset(new_crtc_state) &&
>  		    !new_crtc_state->color_mgmt_changed &&
-- 
Cheers,
	Lyude Paul