From 97ac3204ab9552ab0b4529fa80f072bdad073339 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Thu, 3 Dec 2015 10:49:14 +0100 Subject: [PATCH] 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: Maarten Lankhorst Cc: Maarten Lankhorst Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1449136154-11588-1-git-send-email-daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_atomic_helper.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index d9053ebf4903..74a5fc4deef6 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -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); -- 2.20.1