Re: [Intel-gfx] [PATCH v2 1/3] drm/i915/dp: Make sure all tiled connectors get added to the state with full modeset

From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: Manasi Navare <manasi.d.navare@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH v2 1/3] drm/i915/dp: Make sure all tiled connectors get added to the state with full modeset
Date: Fri, 20 Dec 2019 15:17:27 +0200	[thread overview]
Message-ID: <20191220131727.GJ1208@intel.com> (raw)
In-Reply-To: <20191219215117.929-1-manasi.d.navare@intel.com>

On Thu, Dec 19, 2019 at 01:51:15PM -0800, Manasi Navare wrote:
> In case of tiled displays, all the tiles are linke dto each other
> for transcoder port sync. So in intel_atomic_check() we need to make
> sure that we add all the tiles to the modeset and if one of the
> tiles needs a full modeset then mark all other tiles for a full modeset.
> 
> v2:
> * Change crtc_state scope, remove tile_grp_id (Ville)
> * Use intel_connector_needs_modeset() (Ville)
> * Add modeset_synced_crtcs (Ville)
> * Make sure synced crtcs are forced full modeset
> after fastset check (Ville)
> 
> Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: José Roberto de Souza <jose.souza@intel.com>
> Cc: Matt Roper <matthew.d.roper@intel.com>
> Bugzilla: https://gitlab.freedesktop.org/drm/intel/issues/5
> Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 143 +++++++++++++++++--
>  1 file changed, 131 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index a3f9430493ae..00608d8cef50 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -13910,18 +13910,6 @@ static void intel_crtc_check_fastset(const struct intel_crtc_state *old_crtc_sta
>  	new_crtc_state->uapi.mode_changed = false;
>  	new_crtc_state->update_pipe = true;
>  
> -	/*
> -	 * If we're not doing the full modeset we want to
> -	 * keep the current M/N values as they may be
> -	 * sufficiently different to the computed values
> -	 * to cause problems.
> -	 *
> -	 * FIXME: should really copy more fuzzy state here
> -	 */
> -	new_crtc_state->fdi_m_n = old_crtc_state->fdi_m_n;
> -	new_crtc_state->dp_m_n = old_crtc_state->dp_m_n;
> -	new_crtc_state->dp_m2_n2 = old_crtc_state->dp_m2_n2;
> -	new_crtc_state->has_drrs = old_crtc_state->has_drrs;
>  }

The check vs. copy should really be a separate patch. Otherwise we risk
having to revert the whole thing if something goes wrong.

>  
>  static int intel_crtc_add_planes_to_state(struct intel_atomic_state *state,
> @@ -14032,6 +14020,105 @@ static int intel_atomic_check_crtcs(struct intel_atomic_state *state)
>  	return 0;
>  }
>  
> +static void
> +intel_dp_modeset_synced_crtcs(struct intel_atomic_state *state)

I would remove "dp" from the names of all these functions. The fact
that we only enable port sync on DP outputs is just an implementation
detail we don't have/want to care about in higher level code like this.

> +{
> +	struct intel_crtc_state *new_crtc_state;
> +	struct intel_crtc *crtc;
> +	int i;
> +
> +	for_each_new_intel_crtc_in_state(state, crtc,
> +					 new_crtc_state, i) {
> +		if (is_trans_port_sync_mode(new_crtc_state)) {
> +			new_crtc_state->uapi.mode_changed = true;
> +			new_crtc_state->update_pipe = false;
> +		}
> +	}
> +}
> +
> +static void
> +intel_dp_atomic_check_synced_crtcs(struct intel_atomic_state *state)
> +{
> +	struct intel_crtc_state *new_crtc_state;
> +	struct intel_crtc *crtc;
> +	int i;
> +
> +	for_each_new_intel_crtc_in_state(state, crtc,
> +					 new_crtc_state, i) {
> +		if (!is_trans_port_sync_mode(new_crtc_state) ||
> +		    !needs_modeset(new_crtc_state))
> +			continue;
> +
> +		intel_dp_modeset_synced_crtcs(state);
> +	}

This is not sufficient for the pre-compute_config() check. The point is
that we don't yet necessarily have the synced crtcs in the atomic state
so we have to add them. Please have a look in my branch for what I mean
exactly.

For the check between the fastset check vs. copy this here should work.

> +}
> +
> +static int
> +intel_dp_modeset_all_tiles(struct intel_atomic_state *state, int tile_grp_id)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> +	struct drm_connector *connector;
> +	struct drm_connector_list_iter conn_list_iter;

'conn_iter' is the customary name.

> +
> +	drm_connector_list_iter_begin(&dev_priv->drm, &conn_list_iter);
> +	drm_for_each_connector_iter(connector, &conn_list_iter) {
> +		struct drm_connector_state *conn_iter_state;

'conn_state'

> +		struct drm_crtc_state *crtc_state;
> +
> +		if (!(connector->has_tile &&
> +		      connector->tile_group->id == tile_grp_id))
> +			continue;

or maybe !has_tile || tile_grrp != tile_grp

I find that form a bit easier on the eyes. But either will work.

> +		conn_iter_state = drm_atomic_get_connector_state(&state->base,
> +								 connector);
> +		if (IS_ERR(conn_iter_state)) {
> +			drm_connector_list_iter_end(&conn_list_iter);
> +			return PTR_ERR(conn_iter_state);

nit: could just do 'ret = PTR_ERR(); break;'
     and 'int ret=0;' + 'return ret' at the fars ends of the function.

> +		}
> +
> +		if (!conn_iter_state->crtc)
> +			continue;
> +
> +		crtc_state = drm_atomic_get_crtc_state(&state->base,
> +						       conn_iter_state->crtc);
> +		if (IS_ERR(crtc_state)) {
> +			drm_connector_list_iter_end(&conn_list_iter);
> +			return PTR_ERR(conn_iter_state);
> +		}
> +		crtc_state->mode_changed = true;

Missing drm_atomic_add_affected_planes(). We also need that in the
pre-compute_config() check_synced_crtcs().

> +	}
> +	drm_connector_list_iter_end(&conn_list_iter);
> +
> +	return 0;
> +}
> +
> +static int
> +intel_dp_atomic_check_tiled_conns(struct intel_atomic_state *state)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> +	struct drm_connector *connector;
> +	struct drm_connector_state *old_conn_state, *new_conn_state;
> +	int i, ret;
> +
> +	if (INTEL_GEN(dev_priv) < 11)
> +		return 0;
> +
> +	/* Is tiled, mark all other tiled CRTCs as needing a modeset */
> +	for_each_oldnew_connector_in_state(&state->base, connector,
> +					   old_conn_state, new_conn_state, i) {
> +		if (!connector->has_tile)
> +			continue;
> +		if (!intel_connector_needs_modeset(state, old_conn_state,
> +						   new_conn_state))
> +			continue;
> +
> +		ret = intel_dp_modeset_all_tiles(state, connector->tile_group->id);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  /**
>   * intel_atomic_check - validate state object
>   * @dev: drm device
> @@ -14059,6 +14146,12 @@ static int intel_atomic_check(struct drm_device *dev,
>  	if (ret)
>  		goto fail;
>  
> +	ret = intel_dp_atomic_check_tiled_conns(state);
> +	if (ret)
> +		goto fail;
> +
> +	intel_dp_atomic_check_synced_crtcs(state);
> +
>  	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
>  					    new_crtc_state, i) {
>  		if (!needs_modeset(new_crtc_state)) {
> @@ -14089,6 +14182,32 @@ static int intel_atomic_check(struct drm_device *dev,
>  			any_ms = true;
>  	}
>  
> +	/*
> +	 * In case of port synced crtcs, if one of the synced crtcs
> +	 * needs a full modeset, all other synced crtcs should be
> +	 * forced a full modeset.
> +	 */
> +	intel_dp_atomic_check_synced_crtcs(state);
> +
> +	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
> +					    new_crtc_state, i) {
> +		if (needs_modeset(new_crtc_state))
> +			continue;
> +
> +		/*
> +		 * If we're not doing the full modeset we want to
> +		 * keep the current M/N values as they may be
> +		 * sufficiently different to the computed values
> +		 * to cause problems.
> +		 *
> +		 * FIXME: should really copy more fuzzy state here
> +		 */
> +		new_crtc_state->fdi_m_n = old_crtc_state->fdi_m_n;
> +		new_crtc_state->dp_m_n = old_crtc_state->dp_m_n;
> +		new_crtc_state->dp_m2_n2 = old_crtc_state->dp_m2_n2;
> +		new_crtc_state->has_drrs = old_crtc_state->has_drrs;

Same comment I gave in Jose's patch: Pls keep this in a separate
function. My branch has an example.

> +	}
> +
>  	if (any_ms && !check_digital_port_conflicts(state)) {
>  		DRM_DEBUG_KMS("rejecting conflicting digital port configuration\n");
>  		ret = EINVAL;
> -- 
> 2.19.1

-- 
Ville Syrjälä
Intel
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