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

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.

Cc: stable@vger.kernel.org
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>

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 9b85fcdb391..d5dcf7fe1ee 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -976,6 +976,7 @@ 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 077d40f37b9..fc8a4a940e9 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3960,7 +3960,7 @@
 #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 194df27c89e..95070b2124c 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 f747cb036d8..6f67fa122f8 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3590,6 +3590,7 @@ 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
@@ -3602,8 +3603,12 @@ 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),