linux-kernel - [PATCH 4.4 203/342] drm/dp/mst: Reverse order of MST enable and clearing VC payload table.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20160301234534.476542506@linuxfoundation.org>
Date:	Tue, 01 Mar 2016 23:54:51 +0000
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	<linux-kernel@...r.kernel.org>
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	<stable@...r.kernel.org>,
	Andrey Grodzovsky <Andrey.Grodzovsky@....com>,
	Harry Wentland <harry.wentland@....com>,
	Alex Deucher <alexander.deucher@....com>,
	Dave Airlie <airlied@...hat.com>
Subject: [PATCH 4.4 203/342] drm/dp/mst: Reverse order of MST enable and clearing VC payload table.

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andrey Grodzovsky <Andrey.Grodzovsky@....com>

commit c175cd16df272119534058f28cbd5eeac6ff2d24 upstream.

On DELL U3014 if you clear the table before enabling MST it sometimes
hangs the receiver.

Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky@....com>
Reviewed-by: Harry Wentland <harry.wentland@....com>
Acked-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Dave Airlie <airlied@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/gpu/drm/drm_dp_mst_topology.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1976,6 +1976,12 @@ int drm_dp_mst_topology_mgr_set_mst(stru
 		mgr->mst_primary = mstb;
 		kref_get(&mgr->mst_primary->kref);
 
+		ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
+							 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
+		if (ret < 0) {
+			goto out_unlock;
+		}
+
 		{
 			struct drm_dp_payload reset_pay;
 			reset_pay.start_slot = 0;
@@ -1983,12 +1989,6 @@ int drm_dp_mst_topology_mgr_set_mst(stru
 			drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
 		}
 
-		ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
-					 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
-		if (ret < 0) {
-			goto out_unlock;
-		}
-
 		queue_work(system_long_wq, &mgr->work);
 
 		ret = 0;