On Mon, Aug 03, 2015 at 05:24:11PM +0200, Daniel Vetter wrote:
We've had a few issues with atomic where subtle bugs in the encoder picking logic lead to accidental self-stealing of the encoder, resulting in a NULL connector_state->crtc in update_connector_routing and subsequent.
Linus applied some duct-tape for an mst regression in
commit 27667f4744fc5a0f3e50910e78740bac5670d18b Author: Linus Torvalds torvalds@linux-foundation.org Date: Wed Jul 29 22:18:16 2015 -0700
i915: temporary fix for DP MST docking station NULL pointer dereferenceBut that was incomplete (the code will still oops when debuggin is enabled) and mangled the state even further. So instead WARN and bail out as the more future-proof option.
Cc: Theodore Ts'o tytso@mit.edu Cc: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Daniel Vetter daniel.vetter@intel.com
drivers/gpu/drm/drm_atomic_helper.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 8694ca9beee3..9dcc7280e572 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -234,13 +234,14 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx) } }
- if (WARN_ON(!connector_state->crtc))
return -EINVAL;- connector_state->best_encoder = new_encoder;
- if (connector_state->crtc) {
idx = drm_crtc_index(connector_state->crtc);
- idx = drm_crtc_index(connector_state->crtc);
crtc_state = state->crtc_states[idx];crtc_state->mode_changed = true;- }
crtc_state = state->crtc_states[idx];
crtc_state->mode_changed = true;
DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d]\n", connector->base.id,
Reviewed-by: Thierry Reding treding@nvidia.com