drm/i915/chv: Remove DPIO force latency causing interpair skew issue

Latest version of the "CHV DPIO programming notes" no longer requires writes to TX DW 11 to fix a +2UI interpair skew issue. The current code from April 2014 was actually causing additional skew issues between all TMDS pairs. ver2: added same treatment to intel_dp.c based on Ville's testing. Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
mariux64 · Apr 10, 2015 · af8fcb9 · af8fcb9
1 parent 88f933a
commit af8fcb9
Show file tree

Hide file tree

Showing 2 changed files with 0 additions and 10 deletions.
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
@@ -2742,11 +2742,6 @@ static void chv_pre_enable_dp(struct intel_encoder *encoder)
 
 	/* Program Tx lane latency optimal setting*/
 	for (i = 0; i < 4; i++) {
-		/* Set the latency optimal bit */
-		data = (i == 1) ? 0x0 : 0x6;
-		vlv_dpio_write(dev_priv, pipe, CHV_TX_DW11(ch, i),
-				data << DPIO_FRC_LATENCY_SHFIT);
-
 		/* Set the upar bit */
 		data = (i == 1) ? 0x0 : 0x1;
 		vlv_dpio_write(dev_priv, pipe, CHV_TX_DW14(ch, i),

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1515,11 +1515,6 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder)
 
 	/* Program Tx latency optimal setting */
 	for (i = 0; i < 4; i++) {
-		/* Set the latency optimal bit */
-		data = (i == 1) ? 0x0 : 0x6;
-		vlv_dpio_write(dev_priv, pipe, CHV_TX_DW11(ch, i),
-				data << DPIO_FRC_LATENCY_SHFIT);
-
 		/* Set the upar bit */
 		data = (i == 1) ? 0x0 : 0x1;
 		vlv_dpio_write(dev_priv, pipe, CHV_TX_DW14(ch, i),