[CI v2] drm/fbdev: Fallback to non tiled mode if all tiles not present

[Manasi Navare]

Pushed tod rm-misc-next, thanks a lot Dave all the feedback and reviews.

Regards
Manasi

On Wed, Nov 13, 2019 at 02:29:52PM -0800, Manasi Navare wrote:
> In case of tiled displays, if we hotplug just one connector,
> fbcon currently just selects the preferred mode and if it is
> tiled mode then that becomes a problem if rest of the tiles are
> not present.
> So in the fbdev driver on hotplug when we probe the client modeset,
> if we dont find all the connectors for all tiles, then on a connector
> with one tile, just fallback to the first available non tiled mode
> to display over a single connector.
> On the hotplug of the consecutive tiled connectors, if the tiled mode
> no longer exists because of fbcon size limitation, then return
> no modes for consecutive tiles but retain the non tiled mode
> on the 0th tile.
> Use the same logic in case of connected boot case as well.
> This has been tested with Dell UP328K tiled monitor.
> 
> v2:
> * Set the modes on consecutive hotplugged tiles to no mode
> if tiled mode is pruned (Dave)
> v1:
> * Just handle the 1st connector hotplug case
> * v1 Reviewed-by: Dave Airlie <airlied at redhat.com>
> 
> Suggested-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Suggested-by: Dave Airlie <airlied at redhat.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Dave Airlie <airlied at redhat.com>
> Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> Reviewed-by: Dave Airlie <airlied at redhat.com>
> ---
>  drivers/gpu/drm/drm_client_modeset.c | 70 ++++++++++++++++++++++++++++
>  1 file changed, 70 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c
> index 895b73f23079..f2150a0bac4c 100644
> --- a/drivers/gpu/drm/drm_client_modeset.c
> +++ b/drivers/gpu/drm/drm_client_modeset.c
> @@ -114,6 +114,33 @@ drm_client_find_modeset(struct drm_client_dev *client, struct drm_crtc *crtc)
>  	return NULL;
>  }
>  
> +static struct drm_display_mode *
> +drm_connector_get_tiled_mode(struct drm_connector *connector)
> +{
> +	struct drm_display_mode *mode;
> +
> +	list_for_each_entry(mode, &connector->modes, head) {
> +		if (mode->hdisplay == connector->tile_h_size &&
> +		    mode->vdisplay == connector->tile_v_size)
> +			return mode;
> +	}
> +	return NULL;
> +}
> +
> +static struct drm_display_mode *
> +drm_connector_fallback_non_tiled_mode(struct drm_connector *connector)
> +{
> +	struct drm_display_mode *mode;
> +
> +	list_for_each_entry(mode, &connector->modes, head) {
> +		if (mode->hdisplay == connector->tile_h_size &&
> +		    mode->vdisplay == connector->tile_v_size)
> +			continue;
> +		return mode;
> +	}
> +	return NULL;
> +}
> +
>  static struct drm_display_mode *
>  drm_connector_has_preferred_mode(struct drm_connector *connector, int width, int height)
>  {
> @@ -348,8 +375,14 @@ static bool drm_client_target_preferred(struct drm_connector **connectors,
>  	struct drm_connector *connector;
>  	u64 conn_configured = 0;
>  	int tile_pass = 0;
> +	int num_tiled_conns = 0;
>  	int i;
>  
> +	for (i = 0; i < connector_count; i++) {
> +		if (connectors[i]->has_tile)
> +			num_tiled_conns++;
> +	}
> +
>  retry:
>  	for (i = 0; i < connector_count; i++) {
>  		connector = connectors[i];
> @@ -399,6 +432,28 @@ static bool drm_client_target_preferred(struct drm_connector **connectors,
>  			list_for_each_entry(modes[i], &connector->modes, head)
>  				break;
>  		}
> +		/*
> +		 * In case of tiled mode if all tiles not present fallback to
> +		 * first available non tiled mode.
> +		 * After all tiles are present, try to find the tiled mode
> +		 * for all and if tiled mode not present due to fbcon size
> +		 * limitations, use first non tiled mode only for
> +		 * tile 0,0 and set to no mode for all other tiles.
> +		 */
> +		if (connector->has_tile) {
> +			if (num_tiled_conns <
> +			    connector->num_h_tile * connector->num_v_tile ||
> +			    (connector->tile_h_loc == 0 &&
> +			     connector->tile_v_loc == 0 &&
> +			     !drm_connector_get_tiled_mode(connector))) {
> +				DRM_DEBUG_KMS("Falling back to non tiled mode on Connector %d\n",
> +					      connector->base.id);
> +				modes[i] = drm_connector_fallback_non_tiled_mode(connector);
> +			} else {
> +				modes[i] = drm_connector_get_tiled_mode(connector);
> +			}
> +		}
> +
>  		DRM_DEBUG_KMS("found mode %s\n", modes[i] ? modes[i]->name :
>  			  "none");
>  		conn_configured |= BIT_ULL(i);
> @@ -515,6 +570,7 @@ static bool drm_client_firmware_config(struct drm_client_dev *client,
>  	bool fallback = true, ret = true;
>  	int num_connectors_enabled = 0;
>  	int num_connectors_detected = 0;
> +	int num_tiled_conns = 0;
>  	struct drm_modeset_acquire_ctx ctx;
>  
>  	if (!drm_drv_uses_atomic_modeset(dev))
> @@ -532,6 +588,10 @@ static bool drm_client_firmware_config(struct drm_client_dev *client,
>  	memcpy(save_enabled, enabled, count);
>  	mask = GENMASK(count - 1, 0);
>  	conn_configured = 0;
> +	for (i = 0; i < count; i++) {
> +		if (connectors[i]->has_tile)
> +			num_tiled_conns++;
> +	}
>  retry:
>  	conn_seq = conn_configured;
>  	for (i = 0; i < count; i++) {
> @@ -631,6 +691,16 @@ static bool drm_client_firmware_config(struct drm_client_dev *client,
>  				      connector->name);
>  			modes[i] = &connector->state->crtc->mode;
>  		}
> +		/*
> +		 * In case of tiled modes, if all tiles are not present
> +		 * then fallback to a non tiled mode.
> +		 */
> +		if (connector->has_tile &&
> +		    num_tiled_conns < connector->num_h_tile * connector->num_v_tile) {
> +			DRM_DEBUG_KMS("Falling back to non tiled mode on Connector %d\n",
> +				      connector->base.id);
> +			modes[i] = drm_connector_fallback_non_tiled_mode(connector);
> +		}
>  		crtcs[i] = new_crtc;
>  
>  		DRM_DEBUG_KMS("connector %s on [CRTC:%d:%s]: %dx%d%s\n",
> -- 
> 2.19.1
>