drm/i915: set CPT FDI RX polarity bits based on VBT

commit 3f704fa2778d3fe45e6529825a5c7a8bcbc686f4 upstream.

Check the VBT to see if the machine has inverted FDI RX polarity on
CPT. Based on this bit, set the appropriate bit on the TRANS_CHICKEN2
registers.

This should fix some machines that were showing black screens on all
outputs.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=60029
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

5 files changed, 16 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 01769e2a995..ef99b1c22fc 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -941,6 +941,7 @@ typedef struct drm_i915_private {
 	unsigned int int_crt_support:1;
 	unsigned int lvds_use_ssc:1;
 	unsigned int display_clock_mode:1;
+	unsigned int fdi_rx_polarity_inverted:1;
 	int lvds_ssc_freq;
 	unsigned int bios_lvds_val; /* initial [PCH_]LVDS reg val in VBIOS */
 	struct {
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 848992f67d5..c91124f925d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3827,7 +3827,7 @@
 #define _TRANSB_CHICKEN2	 0xf1064
 #define TRANS_CHICKEN2(pipe) _PIPE(pipe, _TRANSA_CHICKEN2, _TRANSB_CHICKEN2)
 #define  TRANS_CHICKEN2_TIMING_OVERRIDE		(1<<31)
-
+#define  TRANS_CHICKEN2_FDI_POLARITY_REVERSED	(1<<29)
 
 #define SOUTH_CHICKEN1		0xc2000
 #define  FDIA_PHASE_SYNC_SHIFT_OVR	19
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 55ffba1f581..bd833918c49 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -351,12 +351,14 @@ parse_general_features(struct drm_i915_private *dev_priv,
 		dev_priv->lvds_ssc_freq =
 			intel_bios_ssc_frequency(dev, general->ssc_freq);
 		dev_priv->display_clock_mode = general->display_clock_mode;
-		DRM_DEBUG_KMS("BDB_GENERAL_FEATURES int_tv_support %d int_crt_support %d lvds_use_ssc %d lvds_ssc_freq %d display_clock_mode %d\n",
+		dev_priv->fdi_rx_polarity_inverted = general->fdi_rx_polarity_inverted;
+		DRM_DEBUG_KMS("BDB_GENERAL_FEATURES int_tv_support %d int_crt_support %d lvds_use_ssc %d lvds_ssc_freq %d display_clock_mode %d fdi_rx_polarity_inverted %d\n",
 			      dev_priv->int_tv_support,
 			      dev_priv->int_crt_support,
 			      dev_priv->lvds_use_ssc,
 			      dev_priv->lvds_ssc_freq,
-			      dev_priv->display_clock_mode);
+			      dev_priv->display_clock_mode,
+			      dev_priv->fdi_rx_polarity_inverted);
 	}
 }
 
diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
index 36e57f93437..e088d6f0956 100644
--- a/drivers/gpu/drm/i915/intel_bios.h
+++ b/drivers/gpu/drm/i915/intel_bios.h
@@ -127,7 +127,9 @@ struct bdb_general_features {
         /* bits 3 */
 	u8 disable_smooth_vision:1;
 	u8 single_dvi:1;
-	u8 rsvd9:6; /* finish byte */
+	u8 rsvd9:1;
+	u8 fdi_rx_polarity_inverted:1;
+	u8 rsvd10:4; /* finish byte */
 
         /* bits 4 */
 	u8 legacy_monitor_detect;
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index adca00783e6..332b29e5641 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3562,6 +3562,7 @@ static void cpt_init_clock_gating(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int pipe;
+	uint32_t val;
 
 	/*
 	 * On Ibex Peak and Cougar Point, we need to disable clock
@@ -3574,8 +3575,12 @@ static void cpt_init_clock_gating(struct drm_device *dev)
 	/* The below fixes the weird display corruption, a few pixels shifted
 	 * downward, on (only) LVDS of some HP laptops with IVY.
 	 */
-	for_each_pipe(pipe)
-		I915_WRITE(TRANS_CHICKEN2(pipe), TRANS_CHICKEN2_TIMING_OVERRIDE);
+	for_each_pipe(pipe) {
+		val = TRANS_CHICKEN2_TIMING_OVERRIDE;
+		if (dev_priv->fdi_rx_polarity_inverted)
+			val |= TRANS_CHICKEN2_FDI_POLARITY_REVERSED;
+		I915_WRITE(TRANS_CHICKEN2(pipe), val);
+	}
 	/* WADP0ClockGatingDisable */
 	for_each_pipe(pipe) {
 		I915_WRITE(TRANS_CHICKEN1(pipe),