Only DCE5+ asics support DP 1.2.
Noticed by ArtForz on IRC.
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Cc: stable at vger.kernel.org
---
drivers/gpu/drm/radeon/atombios_dp.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
b/drivers/gpu/drm/radeon/atombios_dp.c
index 330f8df..225f6c6 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -291,6 +291,19 @@ static int dp_get_max_dp_pix_clock(int link_rate,
/***** radeon specific DP functions *****/
+static int radeon_dp_get_max_link_rate(struct drm_connector *connector,
+ u8 dpcd[DP_DPCD_SIZE])
+{
+ int max_link_rate;
+
+ if (radeon_connector_is_dp12_capable(connector))
+ max_link_rate = min(drm_dp_max_link_rate(dpcd), 540000);
+ else
+ max_link_rate = min(drm_dp_max_link_rate(dpcd), 270000);
+
+ return max_link_rate;
+}
+
/* First get the min lane# when low rate is used according to pixel clock
* (prefer low rate), second check max lane# supported by DP panel,
* if the max lane# < low rate lane# then use max lane# instead.
@@ -300,7 +313,7 @@ static int radeon_dp_get_dp_lane_number(struct
drm_connector *connector,
int pix_clock)
{
int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector));
- int max_link_rate = drm_dp_max_link_rate(dpcd);
+ int max_link_rate = radeon_dp_get_max_link_rate(connector, dpcd);
int max_lane_num = drm_dp_max_lane_count(dpcd);
int lane_num;
int max_dp_pix_clock;
@@ -338,7 +351,7 @@ static int radeon_dp_get_dp_link_clock(struct drm_connector
*connector,
return 540000;
}
- return drm_dp_max_link_rate(dpcd);
+ return radeon_dp_get_max_link_rate(connector, dpcd);
}
static u8 radeon_dp_encoder_service(struct radeon_device *rdev,
--
1.8.3.1
