From 67fa24b4041436f1a21f7640d1d7ab56d023d7e9 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 8 Jul 2015 23:45:48 +0300 Subject: [PATCH] drm/i915: Always program unique transition scale for CHV MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The docs give you the impression that the unique transition scale value shouldn't matter when unique transition scale is enabled. But as Imre found on BXT (and I verfied also on BSW) the value does matter. So from now on just program the same value 0x9a always. Cc: Imre Deak Signed-off-by: Ville Syrjälä Reviewed-by: Deepak S Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c | 53 +++++++++++++++---------------- drivers/gpu/drm/i915/intel_hdmi.c | 30 +++++++++-------- 2 files changed, 42 insertions(+), 41 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index dcda86a7d68d..da7d1ae18b9b 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3179,6 +3179,12 @@ static uint32_t vlv_signal_levels(struct intel_dp *intel_dp) return 0; } +static bool chv_need_uniq_trans_scale(uint8_t train_set) +{ + return (train_set & DP_TRAIN_PRE_EMPHASIS_MASK) == DP_TRAIN_PRE_EMPH_LEVEL_0 && + (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) == DP_TRAIN_VOLTAGE_SWING_LEVEL_3; +} + static uint32_t chv_signal_levels(struct intel_dp *intel_dp) { struct drm_device *dev = intel_dp_to_dev(intel_dp); @@ -3297,41 +3303,34 @@ static uint32_t chv_signal_levels(struct intel_dp *intel_dp) /* Program swing margin */ for (i = 0; i < 4; i++) { val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW2(ch, i)); + val &= ~DPIO_SWING_MARGIN000_MASK; val |= margin_reg_value << DPIO_SWING_MARGIN000_SHIFT; + + /* + * Supposedly this value shouldn't matter when unique transition + * scale is disabled, but in fact it does matter. Let's just + * always program the same value and hope it's OK. + */ + val &= ~(0xff << DPIO_UNIQ_TRANS_SCALE_SHIFT); + val |= 0x9a << DPIO_UNIQ_TRANS_SCALE_SHIFT; + vlv_dpio_write(dev_priv, pipe, CHV_TX_DW2(ch, i), val); } - /* Disable unique transition scale */ + /* + * The document said it needs to set bit 27 for ch0 and bit 26 + * for ch1. Might be a typo in the doc. + * For now, for this unique transition scale selection, set bit + * 27 for ch0 and ch1. + */ for (i = 0; i < 4; i++) { val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW3(ch, i)); - val &= ~DPIO_TX_UNIQ_TRANS_SCALE_EN; - vlv_dpio_write(dev_priv, pipe, CHV_TX_DW3(ch, i), val); - } - - if (((train_set & DP_TRAIN_PRE_EMPHASIS_MASK) - == DP_TRAIN_PRE_EMPH_LEVEL_0) && - ((train_set & DP_TRAIN_VOLTAGE_SWING_MASK) - == DP_TRAIN_VOLTAGE_SWING_LEVEL_3)) { - - /* - * The document said it needs to set bit 27 for ch0 and bit 26 - * for ch1. Might be a typo in the doc. - * For now, for this unique transition scale selection, set bit - * 27 for ch0 and ch1. - */ - for (i = 0; i < 4; i++) { - val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW3(ch, i)); + if (chv_need_uniq_trans_scale(train_set)) val |= DPIO_TX_UNIQ_TRANS_SCALE_EN; - vlv_dpio_write(dev_priv, pipe, CHV_TX_DW3(ch, i), val); - } - - for (i = 0; i < 4; i++) { - val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW2(ch, i)); - val &= ~(0xff << DPIO_UNIQ_TRANS_SCALE_SHIFT); - val |= (0x9a << DPIO_UNIQ_TRANS_SCALE_SHIFT); - vlv_dpio_write(dev_priv, pipe, CHV_TX_DW2(ch, i), val); - } + else + val &= ~DPIO_TX_UNIQ_TRANS_SCALE_EN; + vlv_dpio_write(dev_priv, pipe, CHV_TX_DW3(ch, i), val); } /* Start swing calculation */ diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c index 7185062c8c9b..c25835f46c62 100644 --- a/drivers/gpu/drm/i915/intel_hdmi.c +++ b/drivers/gpu/drm/i915/intel_hdmi.c @@ -1849,31 +1849,33 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder) for (i = 0; i < 4; i++) { val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW2(ch, i)); + val &= ~DPIO_SWING_MARGIN000_MASK; val |= 102 << DPIO_SWING_MARGIN000_SHIFT; + + /* + * Supposedly this value shouldn't matter when unique transition + * scale is disabled, but in fact it does matter. Let's just + * always program the same value and hope it's OK. + */ + val &= ~(0xff << DPIO_UNIQ_TRANS_SCALE_SHIFT); + val |= 0x9a << DPIO_UNIQ_TRANS_SCALE_SHIFT; + vlv_dpio_write(dev_priv, pipe, CHV_TX_DW2(ch, i), val); } - /* Disable unique transition scale */ + /* + * The document said it needs to set bit 27 for ch0 and bit 26 + * for ch1. Might be a typo in the doc. + * For now, for this unique transition scale selection, set bit + * 27 for ch0 and ch1. + */ for (i = 0; i < 4; i++) { val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW3(ch, i)); val &= ~DPIO_TX_UNIQ_TRANS_SCALE_EN; vlv_dpio_write(dev_priv, pipe, CHV_TX_DW3(ch, i), val); } - /* Additional steps for 1200mV-0dB */ -#if 0 - val = vlv_dpio_read(dev_priv, pipe, VLV_TX_DW3(ch)); - if (ch) - val |= DPIO_TX_UNIQ_TRANS_SCALE_CH1; - else - val |= DPIO_TX_UNIQ_TRANS_SCALE_CH0; - vlv_dpio_write(dev_priv, pipe, VLV_TX_DW3(ch), val); - - vlv_dpio_write(dev_priv, pipe, VLV_TX_DW2(ch), - vlv_dpio_read(dev_priv, pipe, VLV_TX_DW2(ch)) | - (0x9a << DPIO_UNIQ_TRANS_SCALE_SHIFT)); -#endif /* Start swing calculation */ val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW10(ch)); val |= DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3; -- 2.39.2