diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 35c848535d097a6a7b7635ec1c8afaf4af00446f..3d421a60d13789db59a51260aee6294e6386769d 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2233,6 +2233,12 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
if (mst_state) {
WARN_ON(mgr->mst_primary);
+ if (mgr->cbs->pre_enable) {
+ ret = mgr->cbs->pre_enable(mgr);
+ if (ret)
+ goto out_unlock;
+ }
+
/* get dpcd info */
ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
if (ret != DP_RECEIVER_CAP_SIZE) {
@@ -2277,13 +2283,16 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
mgr->mst_state = true;
ret = 0;
} else {
+ if (mgr->cbs->post_disable)
+ mgr->cbs->post_disable(mgr);
+
/* disable MST on the device */
mstb = mgr->mst_primary;
mgr->mst_primary = NULL;
/* this can fail if the device is gone */
drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
- ret = 0;
- memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
+ memset(mgr->payloads, 0,
+ mgr->max_payloads * sizeof(struct drm_dp_payload));
mgr->payload_mask = 0;
set_bit(0, &mgr->payload_mask);
mgr->vcpi_mask = 0;
@@ -2291,6 +2300,9 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
}
out_unlock:
+ if (ret && mst_state && mgr->cbs->post_disable)
+ mgr->cbs->post_disable(mgr);
+
mutex_unlock(&mgr->lock);
if (mstb)
drm_dp_put_mst_branch_device(mstb);
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index 05a58cb36ceec413abc6ba9625c8bfe20b23d36e..35c6efbdd8669dc0af9803a4020f82ab919b2fd2 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -1128,12 +1128,62 @@ nv50_mstm_add_connector(struct drm_dp_mst_topology_mgr *mgr,
return &mstc->connector;
}
+static int
+nv50_mstm_enable(struct nv50_mstm *mstm, int state)
+{
+ struct nouveau_encoder *outp = mstm->outp;
+ struct {
+ struct nv50_disp_mthd_v1 base;
+ struct nv50_disp_sor_dp_mst_link_v0 mst;
+ } args = {
+ .base.version = 1,
+ .base.method = NV50_DISP_MTHD_V1_SOR_DP_MST_LINK,
+ .base.hasht = outp->dcb->hasht,
+ .base.hashm = outp->dcb->hashm,
+ .mst.state = state,
+ };
+ struct nouveau_drm *drm = nouveau_drm(outp->base.base.dev);
+ struct nvif_object *disp = &drm->display->disp.object;
+ int ret;
+
+ /* Even if we're enabling MST, start with disabling the branching unit
+ * to clear any sink-side MST topology state that wasn't set by us
+ */
+ ret = drm_dp_dpcd_writeb(mstm->mgr.aux, DP_MSTM_CTRL, 0);
+ if (ret < 0)
+ return ret;
+
+ if (state) {
+ /* Now, start initializing */
+ ret = drm_dp_dpcd_writeb(mstm->mgr.aux, DP_MSTM_CTRL,
+ DP_MST_EN);
+ if (ret < 0)
+ return ret;
+ }
+
+ return nvif_mthd(disp, 0, &args, sizeof(args));
+}
+
+static int
+nv50_mstm_pre_enable(struct drm_dp_mst_topology_mgr *mgr)
+{
+ return nv50_mstm_enable(nv50_mstm(mgr), true);
+}
+
+static void
+nv50_mstm_post_disable(struct drm_dp_mst_topology_mgr *mgr)
+{
+ nv50_mstm_enable(nv50_mstm(mgr), false);
+}
+
static const struct drm_dp_mst_topology_cbs
nv50_mstm = {
.add_connector = nv50_mstm_add_connector,
.register_connector = nv50_mstm_register_connector,
.destroy_connector = nv50_mstm_destroy_connector,
.hotplug = nv50_mstm_hotplug,
+ .pre_enable = nv50_mstm_pre_enable,
+ .post_disable = nv50_mstm_post_disable,
};
void
@@ -1169,42 +1219,6 @@ nv50_mstm_remove(struct nv50_mstm *mstm)
drm_dp_mst_topology_mgr_set_mst(&mstm->mgr, false);
}
-static int
-nv50_mstm_enable(struct nv50_mstm *mstm, int state)
-{
- struct nouveau_encoder *outp = mstm->outp;
- struct {
- struct nv50_disp_mthd_v1 base;
- struct nv50_disp_sor_dp_mst_link_v0 mst;
- } args = {
- .base.version = 1,
- .base.method = NV50_DISP_MTHD_V1_SOR_DP_MST_LINK,
- .base.hasht = outp->dcb->hasht,
- .base.hashm = outp->dcb->hashm,
- .mst.state = state,
- };
- struct nouveau_drm *drm = nouveau_drm(outp->base.base.dev);
- struct nvif_object *disp = &drm->display->disp.object;
- int ret;
-
- /* Even if we're enabling MST, start with disabling the branching unit
- * to clear any sink-side MST topology state that wasn't set by us
- */
- ret = drm_dp_dpcd_writeb(mstm->mgr.aux, DP_MSTM_CTRL, 0);
- if (ret < 0)
- return ret;
-
- if (state) {
- /* Now, start initializing */
- ret = drm_dp_dpcd_writeb(mstm->mgr.aux, DP_MSTM_CTRL,
- DP_MST_EN);
- if (ret < 0)
- return ret;
- }
-
- return nvif_mthd(disp, 0, &args, sizeof(args));
-}
-
int
nv50_mstm_detect(struct nv50_mstm *mstm, u8 dpcd[8], int allow)
{
@@ -1216,9 +1230,7 @@ nv50_mstm_detect(struct nv50_mstm *mstm, u8 dpcd[8], int allow)
if (!mstm)
return 0;
- mutex_lock(&mstm->mgr.lock);
-
- old_state = mstm->mgr.mst_state;
+ old_state = READ_ONCE(mstm->mgr.mst_state);
new_state = old_state;
aux = mstm->mgr.aux;
@@ -1232,7 +1244,7 @@ nv50_mstm_detect(struct nv50_mstm *mstm, u8 dpcd[8], int allow)
} else if (dpcd[0] >= 0x12) {
ret = drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &dpcd[1]);
if (ret < 0)
- goto probe_error;
+ return ret;
if (!(dpcd[1] & DP_MST_CAP))
dpcd[0] = 0x11;
@@ -1240,26 +1252,10 @@ nv50_mstm_detect(struct nv50_mstm *mstm, u8 dpcd[8], int allow)
new_state = allow;
}
- if (new_state == old_state) {
- mutex_unlock(&mstm->mgr.lock);
+ if (new_state == old_state)
return new_state;
- }
-
- ret = nv50_mstm_enable(mstm, new_state);
- if (ret)
- goto probe_error;
- mutex_unlock(&mstm->mgr.lock);
-
- ret = drm_dp_mst_topology_mgr_set_mst(&mstm->mgr, new_state);
- if (ret)
- return nv50_mstm_enable(mstm, 0);
-
- return new_state;
-
-probe_error:
- mutex_unlock(&mstm->mgr.lock);
- return ret;
+ return drm_dp_mst_topology_mgr_set_mst(&mstm->mgr, new_state);
}
static void
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index c252e42677e5f7a3f1d7d7dae399c9733d55694a..46292ed5f50ed7ff9c6e538580bf39cf3b06586c 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -326,11 +326,15 @@ struct drm_dp_sideband_msg_tx {
struct drm_dp_mst_topology_mgr;
struct drm_dp_mst_topology_cbs {
/* create a connector for a port */
- struct drm_connector *(*add_connector)(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, const char *path);
+ struct drm_connector *(*add_connector)(struct drm_dp_mst_topology_mgr *mgr,
+ struct drm_dp_mst_port *port,
+ const char *path);
void (*register_connector)(struct drm_connector *connector);
void (*destroy_connector)(struct drm_dp_mst_topology_mgr *mgr,
struct drm_connector *connector);
void (*hotplug)(struct drm_dp_mst_topology_mgr *mgr);
+ int (*pre_enable)(struct drm_dp_mst_topology_mgr *mgr);
+ void (*post_disable)(struct drm_dp_mst_topology_mgr *mgr);
};