As mentioned in the previous commit, we currently prevent new modesets on recently-removed MST connectors by returning no encoder from our ->best_encoder() callback once the MST port has disappeared. This is wrong however, because it prevents legacy modesetting users from being able to disable CRTCs on MST connectors after the connector's respective topology has disappeared.

So, fix this by instead using the new drm_dp_mst_connector_atomic_check() helper instead while always returning a valid encoder from ->best_encoder().

Signed-off-by: Lyude Paul lyude@redhat.com Cc: stable@vger.kernel.org --- drivers/gpu/drm/nouveau/dispnv50/disp.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c index 9da0bdfe1e1c..8d6f6ee9bc75 100644 --- a/drivers/gpu/drm/nouveau/dispnv50/disp.c +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c @@ -881,22 +881,16 @@ nv50_mstc_atomic_best_encoder(struct drm_connector *connector, { struct nv50_head *head = nv50_head(connector_state->crtc); struct nv50_mstc *mstc = nv50_mstc(connector); - if (mstc->port) { - struct nv50_mstm *mstm = mstc->mstm; - return &mstm->msto[head->base.index]->encoder; - } - return NULL; + + return &mstc->mstm->msto[head->base.index]->encoder; }

static struct drm_encoder * nv50_mstc_best_encoder(struct drm_connector *connector) { struct nv50_mstc *mstc = nv50_mstc(connector); - if (mstc->port) { - struct nv50_mstm *mstm = mstc->mstm; - return &mstm->msto[0]->encoder; - } - return NULL; + + return &mstc->mstm->msto[0]->encoder; }

static enum drm_mode_status @@ -926,10 +920,21 @@ nv50_mstc_get_modes(struct drm_connector *connector) return ret; }

+static int +nv50_mstc_atomic_check(struct drm_connector *connector, + struct drm_connector_state *state) +{ + struct nv50_mstc *mstc = nv50_mstc(connector); + + return drm_dp_mst_connector_atomic_check(connector, state, + &mstc->mstm->mgr); +} + static const struct drm_connector_helper_funcs nv50_mstc_help = { .get_modes = nv50_mstc_get_modes, .mode_valid = nv50_mstc_mode_valid, + .atomic_check = nv50_mstc_atomic_check, .best_encoder = nv50_mstc_best_encoder, .atomic_best_encoder = nv50_mstc_atomic_best_encoder, };