linux-kernel - [WIP PATCH 10/15] drm/nouveau: Stop unsetting mstc->port, use malloc refs

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Date:   Thu, 13 Dec 2018 20:25:39 -0500
From:   Lyude Paul <lyude@...hat.com>
To:     dri-devel@...ts.freedesktop.org, nouveau@...ts.freedesktop.org,
        intel-gfx@...ts.freedesktop.org, amd-gfx@...ts.freedesktop.org
Cc:     Daniel Vetter <daniel@...ll.ch>, Dave Airlie <airlied@...il.com>,
        Harry Wentland <harry.wentland@....com>,
        Jerry Zuo <Jerry.Zuo@....com>, Ben Skeggs <bskeggs@...hat.com>,
        David Airlie <airlied@...ux.ie>,
        Ilia Mirkin <imirkin@...m.mit.edu>,
        Sean Paul <seanpaul@...omium.org>, linux-kernel@...r.kernel.org
Subject: [WIP PATCH 10/15] drm/nouveau: Stop unsetting mstc->port, use malloc refs

Same as we did for i915, but for nouveau this time. Additionally, we
grab a malloc reference to the port that lasts for the entire lifetime
of nv50_mstc, which gives us the guarantee that mstc->port will always
point to valid memory for as long as the mstc stays around.

Signed-off-by: Lyude Paul <lyude@...hat.com>
---
 drivers/gpu/drm/nouveau/dispnv50/disp.c | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index 982054bbcc8b..157d208d37b5 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -709,8 +709,7 @@ nv50_msto_cleanup(struct nv50_msto *msto)
 
 	NV_ATOMIC(drm, "%s: msto cleanup\n", msto->encoder.name);
 
-	if (mstc->port)
-		drm_dp_mst_deallocate_vcpi(&mstm->mgr, mstc->port);
+	drm_dp_mst_deallocate_vcpi(&mstm->mgr, mstc->port);
 
 	msto->mstc = NULL;
 	msto->head = NULL;
@@ -735,7 +734,7 @@ nv50_msto_prepare(struct nv50_msto *msto)
 	};
 
 	NV_ATOMIC(drm, "%s: msto prepare\n", msto->encoder.name);
-	if (mstc->port && mstc->port->vcpi.vcpi > 0) {
+	if (mstc->port->vcpi.vcpi > 0) {
 		struct drm_dp_payload *payload = nv50_msto_payload(msto);
 		if (payload) {
 			args.vcpi.start_slot = payload->start_slot;
@@ -832,8 +831,7 @@ nv50_msto_disable(struct drm_encoder *encoder)
 	struct nv50_mstc *mstc = msto->mstc;
 	struct nv50_mstm *mstm = mstc->mstm;
 
-	if (mstc->port)
-		drm_dp_mst_reset_vcpi_slots(&mstm->mgr, mstc->port);
+	drm_dp_mst_reset_vcpi_slots(&mstm->mgr, mstc->port);
 
 	mstm->outp->update(mstm->outp, msto->head->base.index, NULL, 0, 0);
 	mstm->modified = true;
@@ -945,7 +943,7 @@ nv50_mstc_detect(struct drm_connector *connector, bool force)
 	enum drm_connector_status conn_status;
 	int ret;
 
-	if (!mstc->port)
+	if (drm_connector_is_unregistered(connector))
 		return connector_status_disconnected;
 
 	ret = pm_runtime_get_sync(connector->dev->dev);
@@ -966,8 +964,7 @@ nv50_mstc_destroy(struct drm_connector *connector)
 	struct nv50_mstc *mstc = nv50_mstc(connector);
 
 	drm_connector_cleanup(&mstc->connector);
-	if (mstc->port)
-		drm_dp_mst_put_port_malloc(mstc->port);
+	drm_dp_mst_put_port_malloc(mstc->port);
 
 	kfree(mstc);
 }
@@ -1081,11 +1078,6 @@ nv50_mstm_destroy_connector(struct drm_dp_mst_topology_mgr *mgr,
 
 	drm_fb_helper_remove_one_connector(&drm->fbcon->helper, &mstc->connector);
 
-	drm_modeset_lock(&drm->dev->mode_config.connection_mutex, NULL);
-	drm_dp_mst_put_port_malloc(mstc->port);
-	mstc->port = NULL;
-	drm_modeset_unlock(&drm->dev->mode_config.connection_mutex);
-
 	drm_connector_put(&mstc->connector);
 }
 
-- 
2.19.2