Commit 9dc0487d authored by Lyude's avatar Lyude Committed by Dave Airlie

drm/dp/mst: Restore primary hub guid on resume

Some hubs are forgetful, and end up forgetting whatever GUID we set
previously after we do a suspend/resume cycle. This can lead to
hotplugging breaking (along with probably other things) since the hub
will start sending connection notifications with the wrong GUID. As
such, we need to check on resume whether or not the GUID the hub is
giving us is valid.
Signed-off-by: default avatarLyude <cpaul@redhat.com>
Reviewed-by: default avatarHarry Wentland <harry.wentland@amd.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460580618-7421-1-git-send-email-cpaul@redhat.com
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 263efde3
...@@ -2136,6 +2136,8 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr) ...@@ -2136,6 +2136,8 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
if (mgr->mst_primary) { if (mgr->mst_primary) {
int sret; int sret;
u8 guid[16];
sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE); sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
if (sret != DP_RECEIVER_CAP_SIZE) { if (sret != DP_RECEIVER_CAP_SIZE) {
DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n"); DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
...@@ -2150,6 +2152,16 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr) ...@@ -2150,6 +2152,16 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
ret = -1; ret = -1;
goto out_unlock; goto out_unlock;
} }
/* Some hubs forget their guids after they resume */
sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
if (sret != 16) {
DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
ret = -1;
goto out_unlock;
}
drm_dp_check_mstb_guid(mgr->mst_primary, guid);
ret = 0; ret = 0;
} else } else
ret = -1; ret = -1;
......
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