DP 1.2 compatible displays may report a 5.4Gbps maximum bandwidth which
the driver will treat as an invalid value and use 1.62Gbps instead. Fix
this by capping to 2.7Gbps anything beyond the DP 1.1 bandwidth range.
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
drivers/gpu/drm/i915/intel_dp.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 11eb697..c6dd61f 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -71,11 +71,16 @@ intel_dp_max_link_bw(struct intel_dp *intel_dp)
{
int max_link_bw = intel_dp->dpcd[DP_MAX_LINK_RATE];
+ if (max_link_bw > DP_LINK_BW_2_7)
+ return DP_LINK_BW_2_7;
+
switch (max_link_bw) {
case DP_LINK_BW_1_62:
case DP_LINK_BW_2_7:
break;
default:
+ WARN(1, "invalid max DP link bw val %x, using 1.62Gbps\n",
+ max_link_bw);
max_link_bw = DP_LINK_BW_1_62;
break;
}
--
1.8.1.2
