From 2cdfe6c8efb9d7dab577d610b6cdab198482cec1 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Fri, 4 Oct 2013 15:08:48 +0300 Subject: [PATCH] drm/i915/dp: update training set in a burst write with training pattern set MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The DP spec allows this, and requires it when full link training is started with non-minimum voltage swing and/or non-zero pre-emphasis. Signed-off-by: Jani Nikula Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 377014783e74..bee09e16725c 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -2297,7 +2297,8 @@ intel_dp_set_link_train(struct intel_dp *intel_dp, struct drm_device *dev = intel_dig_port->base.base.dev; struct drm_i915_private *dev_priv = dev->dev_private; enum port port = intel_dig_port->port; - int ret; + uint8_t buf[sizeof(intel_dp->train_set) + 1]; + int ret, len; if (HAS_DDI(dev)) { uint32_t temp = I915_READ(DP_TP_CTL(port)); @@ -2367,22 +2368,21 @@ intel_dp_set_link_train(struct intel_dp *intel_dp, I915_WRITE(intel_dp->output_reg, *DP); POSTING_READ(intel_dp->output_reg); - ret = intel_dp_aux_native_write_1(intel_dp, DP_TRAINING_PATTERN_SET, - dp_train_pat); - if (ret != 1) - return false; - - if ((dp_train_pat & DP_TRAINING_PATTERN_MASK) != + buf[0] = dp_train_pat; + if ((dp_train_pat & DP_TRAINING_PATTERN_MASK) == DP_TRAINING_PATTERN_DISABLE) { - ret = intel_dp_aux_native_write(intel_dp, - DP_TRAINING_LANE0_SET, - intel_dp->train_set, - intel_dp->lane_count); - if (ret != intel_dp->lane_count) - return false; + /* don't write DP_TRAINING_LANEx_SET on disable */ + len = 1; + } else { + /* DP_TRAINING_LANEx_SET follow DP_TRAINING_PATTERN_SET */ + memcpy(buf + 1, intel_dp->train_set, intel_dp->lane_count); + len = intel_dp->lane_count + 1; } - return true; + ret = intel_dp_aux_native_write(intel_dp, DP_TRAINING_PATTERN_SET, + buf, len); + + return ret == len; } static bool -- 2.20.1