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 for sinks reporting a 5.4Gbps max bw. Also add a warning for reserved values. v2: - allow only bw values explicitly listed in the DP standard (Daniel, Chris) 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..7db2cd7 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -75,7 +75,12 @@ intel_dp_max_link_bw(struct intel_dp *intel_dp) case DP_LINK_BW_1_62: case DP_LINK_BW_2_7: break; + case DP_LINK_BW_5_4: /* 1.2 capable displays may advertise higher bw */ + max_link_bw = 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
