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 <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449136154-11588-1-git-send-email-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter 2015-12-03 10:49:14 +01:00
parent 1494276000
commit 97ac3204ab

View file

@ -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);