[PATCH 3.19.y-ckt 073/210] drm/dp/mst: fix in RAD element access

From: Kamal Mostafa
Date: Thu Jan 28 2016 - 21:03:51 EST


3.19.8-ckt14 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Mykola Lysenko <Mykola.Lysenko@xxxxxxx>

commit 7a11a334aa6af4c65c6a0d81b60c97fc18673532 upstream.

This is needed to receive correct port
number from RAD, so MSTB could be found

Acked-by: Dave Airlie <airlied@xxxxxxxxx>
Signed-off-by: Mykola Lysenko <Mykola.Lysenko@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 4710d2f..85aebb2 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1035,7 +1035,7 @@ static void build_mst_prop_path(struct drm_dp_mst_port *port,
snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
for (i = 0; i < (mstb->lct - 1); i++) {
int shift = (i % 2) ? 0 : 4;
- int port_num = mstb->rad[i / 2] >> shift;
+ int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
snprintf(temp, sizeof(temp), "-%d", port_num);
strlcat(proppath, temp, proppath_size);
}
@@ -1185,7 +1185,7 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_

for (i = 0; i < lct - 1; i++) {
int shift = (i % 2) ? 0 : 4;
- int port_num = rad[i / 2] >> shift;
+ int port_num = (rad[i / 2] >> shift) & 0xf;

list_for_each_entry(port, &mstb->ports, next) {
if (port->port_num == port_num) {
--
1.9.1