[Intel-gfx] [PATCH 1/2] drm/i915: Don't bypass LRC on CHV

ville.syrjala at linux.intel.com ville.syrjala at linux.intel.com
Tue Sep 8 08:05:44 PDT 2015


From: Ville Syrjälä <ville.syrjala at linux.intel.com>

The docs are unclear as usual, so it's not clear whether LRC should be
bypassed, performed normally or GRC code should be used as the LRC code.
Some old docs stated that LRC bypass ought to be used, more recent ones
no longer say that. Some docs indicated that we could use GRC as the LRC
code on CHV, but the BIOS doesn't do that, so let's not do it either.

Besides to enable LRC bypass properly, I believe we should set the bit
already before deasserting cmnreset.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c   | 5 -----
 drivers/gpu/drm/i915/intel_hdmi.c | 5 -----
 2 files changed, 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 45ab25e..825d5ab 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3416,11 +3416,6 @@ static uint32_t chv_signal_levels(struct intel_dp *intel_dp)
 		vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW10(ch), val);
 	}
 
-	/* LRC Bypass */
-	val = vlv_dpio_read(dev_priv, pipe, CHV_CMN_DW30);
-	val |= DPIO_LRC_BYPASS;
-	vlv_dpio_write(dev_priv, pipe, CHV_CMN_DW30, val);
-
 	mutex_unlock(&dev_priv->sb_lock);
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index feb31d8..9d7923d 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1941,11 +1941,6 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder)
 	val |= DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3;
 	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW10(ch), val);
 
-	/* LRC Bypass */
-	val = vlv_dpio_read(dev_priv, pipe, CHV_CMN_DW30);
-	val |= DPIO_LRC_BYPASS;
-	vlv_dpio_write(dev_priv, pipe, CHV_CMN_DW30, val);
-
 	mutex_unlock(&dev_priv->sb_lock);
 
 	intel_hdmi->set_infoframes(&encoder->base,
-- 
2.4.6



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