| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.1 131/267] drm/dp/mst: take lock around looking up the branch device on hpd irq | Date | Fri, 31 Jul 2015 12:39:42 -0700 |
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4.1-stable review patch. If anyone has any objections, please let me know.
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From: Dave Airlie <airlied@redhat.com>
commit 9eb1e57f564d4e6e10991402726cc83fe0b9172f upstream.
If we are doing an MST transaction and we've gotten HPD and we lookup the device from the incoming msg, we should take the mgr lock around it, so that mst_primary and mstb->ports are valid.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1171,6 +1171,8 @@ static struct drm_dp_mst_branch *drm_dp_ struct drm_dp_mst_port *port; int i; /* find the port by iterating down */ + + mutex_lock(&mgr->lock); mstb = mgr->mst_primary; for (i = 0; i < lct - 1; i++) { @@ -1190,6 +1192,7 @@ static struct drm_dp_mst_branch *drm_dp_ } } kref_get(&mstb->kref); + mutex_unlock(&mgr->lock); return mstb; }
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