drm/i915: Clear TX FIFO reset master override bits on chv

Clear the override bits to make sure the hardware manages
the TX FIFO reset master on its own.

v2: Squash with the earlier attempt at forcing the override bits

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -796,6 +796,8 @@ enum punit_power_well {
 #define _VLV_PCS_DW0_CH1		0x8400
 #define   DPIO_PCS_TX_LANE2_RESET	(1<<16)
 #define   DPIO_PCS_TX_LANE1_RESET	(1<<7)
+#define   DPIO_LEFT_TXFIFO_RST_MASTER2	(1<<4)
+#define   DPIO_RIGHT_TXFIFO_RST_MASTER2	(1<<3)
 #define VLV_PCS_DW0(ch) _PORT(ch, _VLV_PCS_DW0_CH0, _VLV_PCS_DW0_CH1)
 
 #define _VLV_PCS01_DW0_CH0		0x200
@@ -872,8 +874,18 @@ enum punit_power_well {
 
 #define _VLV_PCS_DW11_CH0		0x822c
 #define _VLV_PCS_DW11_CH1		0x842c
+#define   DPIO_LANEDESKEW_STRAP_OVRD	(1<<3)
+#define   DPIO_LEFT_TXFIFO_RST_MASTER	(1<<1)
+#define   DPIO_RIGHT_TXFIFO_RST_MASTER	(1<<0)
 #define VLV_PCS_DW11(ch) _PORT(ch, _VLV_PCS_DW11_CH0, _VLV_PCS_DW11_CH1)
 
+#define _VLV_PCS01_DW11_CH0		0x022c
+#define _VLV_PCS23_DW11_CH0		0x042c
+#define _VLV_PCS01_DW11_CH1		0x262c
+#define _VLV_PCS23_DW11_CH1		0x282c
+#define VLV_PCS01_DW11(ch) _PORT(ch, _VLV_PCS01_DW0_CH0, _VLV_PCS01_DW0_CH1)
+#define VLV_PCS23_DW11(ch) _PORT(ch, _VLV_PCS23_DW0_CH0, _VLV_PCS23_DW0_CH1)
+
 #define _VLV_PCS_DW12_CH0		0x8230
 #define _VLV_PCS_DW12_CH1		0x8430
 #define VLV_PCS_DW12(ch) _PORT(ch, _VLV_PCS_DW12_CH0, _VLV_PCS_DW12_CH1)

drivers/gpu/drm/i915/intel_dp.c

@@ -2731,6 +2731,15 @@ static void chv_pre_enable_dp(struct intel_encoder *encoder)
 
 	mutex_lock(&dev_priv->dpio_lock);
 
+	/* allow hardware to manage TX FIFO reset source */
+	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW11(ch));
+	val &= ~DPIO_LANEDESKEW_STRAP_OVRD;
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW11(ch), val);
+
+	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW11(ch));
+	val &= ~DPIO_LANEDESKEW_STRAP_OVRD;
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW11(ch), val);
+
 	/* Deassert soft data lane reset*/
 	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW1(ch));
 	val |= CHV_PCS_REQ_SOFTRESET_EN;

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1400,6 +1400,15 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder)
 
 	mutex_lock(&dev_priv->dpio_lock);
 
+	/* allow hardware to manage TX FIFO reset source */
+	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW11(ch));
+	val &= ~DPIO_LANEDESKEW_STRAP_OVRD;
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW11(ch), val);
+
+	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW11(ch));
+	val &= ~DPIO_LANEDESKEW_STRAP_OVRD;
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW11(ch), val);
+
 	/* Deassert soft data lane reset*/
 	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW1(ch));
 	val |= CHV_PCS_REQ_SOFTRESET_EN;