From af8fcb9c58f1b2f02ddc04ba64710aaa52da00db Mon Sep 17 00:00:00 2001 From: Clint Taylor Date: Thu, 9 Apr 2015 13:42:06 -0700 Subject: [PATCH] drm/i915/chv: Remove DPIO force latency causing interpair skew issue MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Ville Syrjälä Tested-by: Ville Syrjälä Signed-off-by: Clint Taylor Signed-off-by: Jani Nikula --- 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 8e0d1015fb36..60e8d5d77fc5 100644 --- 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 index cacbafdad3ab..bfabd5fd9334 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), -- 2.20.1