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Commit 97ac3204 authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm/atomic-helper: Reject attempts at re-stealing encoders 



This can happen when we run out of encoders for a multi-crtc modeset,
or also when userspace is silly and tries to clone multiple connectors
that need the same encoder on the same crtc.

Reported-and-Tested-and-Reviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449136154-11588-1-git-send-email-daniel.vetter@ffwll.ch
parent 14942760

drivers/gpu/drm/drm_atomic_helper.c

+28 −0
Original line number Diff line number Diff line
@@ -80,6 +80,27 @@ drm_atomic_helper_plane_changed(struct drm_atomic_state *state, 
	}

}



static bool

check_pending_encoder_assignment(struct drm_atomic_state *state,

				 struct drm_encoder *new_encoder,

				 struct drm_connector *new_connector)

{

	struct drm_connector *connector;

	struct drm_connector_state *conn_state;

	int i;



	for_each_connector_in_state(state, connector, conn_state, i) {

		if (conn_state->best_encoder != new_encoder)

			continue;



		/* encoder already assigned and we're trying to re-steal it! */

		if (connector->state->best_encoder != conn_state->best_encoder)

			return false;

	}



	return true;

}



static struct drm_crtc *

get_current_crtc_for_encoder(struct drm_device *dev,

			     struct drm_encoder *encoder)
@@ -229,6 +250,13 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx) 
		return 0;

	}



	if (!check_pending_encoder_assignment(state, new_encoder, connector)) {

		DRM_DEBUG_ATOMIC("Encoder for [CONNECTOR:%d:%s] already assigned\n",

				 connector->base.id,

				 connector->name);

		return -EINVAL;

	}



	encoder_crtc = get_current_crtc_for_encoder(state->dev,

						    new_encoder);