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

clinton.a.taylor
2015-04-09T17:19:12Z

From: Clint Taylor <clinton.a.taylor@intel.com>

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.

Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
---
drivers/gpu/drm/i915/intel_hdmi.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 26222e6..3cef326 100644
--- 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),
--
1.7.9.5