drm/i915: Program chicken bit during DP MST sequence on TGL+

A new step has been added to the DP modeset sequences for all platforms
with display version 12 and beyond:  if enabling DP MST with FEC, we
need to set a chicken bit before enabling the transcoder.  The chicken
bit should be disabled again before disabling the transcoder (which we
can do unconditionally since it shouldn't be set anyway in non-MST
cases).

Bspec: 49190, 54128, 55424
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723170618.1477415-1-matthew.d.roper@intel.com
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>

drivers/gpu/drm/i915/display/intel_display.c

@@ -1035,6 +1035,10 @@ void intel_disable_pipe(const struct intel_crtc_state *old_crtc_state)
 	if (!IS_I830(dev_priv))
 		val &= ~PIPECONF_ENABLE;
 
+	if (DISPLAY_VER(dev_priv) >= 12)
+		intel_de_rmw(dev_priv, CHICKEN_TRANS(cpu_transcoder),
+			     FECSTALL_DIS_DPTSTREAM_DPTTG, 0);
+
 	intel_de_write(dev_priv, reg, val);
 	if ((val & PIPECONF_ENABLE) == 0)
 		intel_wait_for_pipe_off(old_crtc_state);

drivers/gpu/drm/i915/display/intel_dp_mst.c

@@ -542,20 +542,16 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
 	struct intel_digital_port *dig_port = intel_mst->primary;
 	struct intel_dp *intel_dp = &dig_port->dp;
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
-	u32 val;
+	enum transcoder trans = pipe_config->cpu_transcoder;
 
 	drm_WARN_ON(&dev_priv->drm, pipe_config->has_pch_encoder);
 
 	clear_act_sent(encoder, pipe_config);
 
 	intel_ddi_enable_transcoder_func(encoder, pipe_config);
 
-	val = intel_de_read(dev_priv,
-			    TRANS_DDI_FUNC_CTL(pipe_config->cpu_transcoder));
-	val |= TRANS_DDI_DP_VC_PAYLOAD_ALLOC;
-	intel_de_write(dev_priv,
-		       TRANS_DDI_FUNC_CTL(pipe_config->cpu_transcoder),
-		       val);
+	intel_de_rmw(dev_priv, TRANS_DDI_FUNC_CTL(trans), 0,
+		     TRANS_DDI_DP_VC_PAYLOAD_ALLOC);
 
 	drm_dbg_kms(&dev_priv->drm, "active links %d\n",
 		    intel_dp->active_mst_links);
@@ -564,6 +560,10 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
 
 	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
 
+	if (DISPLAY_VER(dev_priv) >= 12 && pipe_config->fec_enable)
+		intel_de_rmw(dev_priv, CHICKEN_TRANS(trans), 0,
+			     FECSTALL_DIS_DPTSTREAM_DPTTG);
+
 	intel_enable_pipe(pipe_config);
 
 	intel_crtc_vblank_on(pipe_config);

drivers/gpu/drm/i915/i915_reg.h

@@ -8167,15 +8167,16 @@ enum {
 					    [TRANSCODER_B] = _CHICKEN_TRANS_B, \
 					    [TRANSCODER_C] = _CHICKEN_TRANS_C, \
 					    [TRANSCODER_D] = _CHICKEN_TRANS_D))
-#define  HSW_FRAME_START_DELAY_MASK	(3 << 27)
-#define  HSW_FRAME_START_DELAY(x)	((x) << 27) /* 0-3 */
-#define  VSC_DATA_SEL_SOFTWARE_CONTROL	(1 << 25) /* GLK and CNL+ */
-#define  DDI_TRAINING_OVERRIDE_ENABLE	(1 << 19)
-#define  DDI_TRAINING_OVERRIDE_VALUE	(1 << 18)
-#define  DDIE_TRAINING_OVERRIDE_ENABLE	(1 << 17) /* CHICKEN_TRANS_A only */
-#define  DDIE_TRAINING_OVERRIDE_VALUE	(1 << 16) /* CHICKEN_TRANS_A only */
-#define  PSR2_ADD_VERTICAL_LINE_COUNT   (1 << 15)
-#define  PSR2_VSC_ENABLE_PROG_HEADER    (1 << 12)
+#define  HSW_FRAME_START_DELAY_MASK	REG_GENMASK(28, 27)
+#define  HSW_FRAME_START_DELAY(x)	REG_FIELD_PREP(HSW_FRAME_START_DELAY_MASK, x)
+#define  VSC_DATA_SEL_SOFTWARE_CONTROL	REG_BIT(25) /* GLK and CNL+ */
+#define  FECSTALL_DIS_DPTSTREAM_DPTTG	REG_BIT(23)
+#define  DDI_TRAINING_OVERRIDE_ENABLE	REG_BIT(19)
+#define  DDI_TRAINING_OVERRIDE_VALUE	REG_BIT(18)
+#define  DDIE_TRAINING_OVERRIDE_ENABLE	REG_BIT(17) /* CHICKEN_TRANS_A only */
+#define  DDIE_TRAINING_OVERRIDE_VALUE	REG_BIT(16) /* CHICKEN_TRANS_A only */
+#define  PSR2_ADD_VERTICAL_LINE_COUNT	REG_BIT(15)
+#define  PSR2_VSC_ENABLE_PROG_HEADER	REG_BIT(12)
 
 #define DISP_ARB_CTL	_MMIO(0x45000)
 #define  DISP_FBC_MEMORY_WAKE		(1 << 31)