blob: 93ce9d8c69af9d4bbe862a87f4d5499e80c60a65 [file] [log] [blame]
From b53c54ca82a560b896552b3ef034ce3368d9c189 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@intel.com>
Date: Tue, 9 Jul 2013 17:05:26 +0300
Subject: drm/i915: fix lane bandwidth capping for DP 1.2 sinks
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@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit d4eead50eb206b875f54f66cc0f6ec7d54122c28)
Signed-off-by: Darren Hart <dvhart@linux.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 47713d6aa4a5..3aed1fe0aa51 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;
}
--
1.8.5.rc3