Re: [PATCH 6/7] drm/i915: Try harder during dp pattern 1 link training

Keith Packard
2011-11-02T17:38:16Z

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On Wed, 02 Nov 2011 09:12:13 +0000, Chris Wilson <chris@chris-wilson.co.uk> wrote:

> This would seem to be a separate chunk to initiate training on only the
> lanes we intend to use.
> -Chris

Here's that patch separated out:

commit e7fecae483754ca9a42312be18f58ceb454702fe
Author: Keith Packard <keithp@keithp.com>
Date: Wed Nov 2 10:17:59 2011 -0700

drm/i915: Initiate DP link training only on the lanes we'll be using

Limit the link training setting command to the lanes needed for the
current mode. It seems vaguely possible that a monitor will try to
train the other lanes and fail in some way, so this seems like the
safer plan.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 0a4fa64..02b56ce 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1567,8 +1567,9 @@ intel_dp_set_link_train(struct intel_dp *intel_dp,

ret = intel_dp_aux_native_write(intel_dp,
DP_TRAINING_LANE0_SET,
- intel_dp->train_set, 4);
- if (ret != 4)
+ intel_dp->train_set,
+ intel_dp->lane_count);
+ if (ret != intel_dp->lane_count)
return false;

return true;

--
keith.packard@intel.com

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