[PATCH 3/4] drm/dp/mst: fix in MSTB RAD initialization
Alex Deucher
alexdeucher at gmail.com
Mon Jan 4 09:26:58 PST 2016
From: Mykola Lysenko <Mykola.Lysenko at amd.com>
This fix is needed to support more then two
branch displays, so RAD address consist at
least of 2 elements
Acked-by: Dave Airlie <airlied at gmail.com>
Signed-off-by: Mykola Lysenko <Mykola.Lysenko at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Cc: stable at vger.kernel.org
---
drivers/gpu/drm/drm_dp_mst_topology.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index ca92a32..d809ce8 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -978,17 +978,17 @@ static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u
static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
u8 *rad)
{
- int lct = port->parent->lct;
+ int parent_lct = port->parent->lct;
int shift = 4;
- int idx = lct / 2;
- if (lct > 1) {
- memcpy(rad, port->parent->rad, idx);
- shift = (lct % 2) ? 4 : 0;
+ int idx = (parent_lct - 1) / 2;
+ if (parent_lct > 1) {
+ memcpy(rad, port->parent->rad, idx + 1);
+ shift = (parent_lct % 2) ? 4 : 0;
} else
rad[0] = 0;
rad[idx] |= port->port_num << shift;
- return lct + 1;
+ return parent_lct + 1;
}
/*
--
2.5.0
More information about the dri-devel
mailing list