[Intel-gfx] [PATCH v3] drm/i915/display/tgl: Do not program clockgating

[José Roberto de Souza]

Talked with HW team and this is a left over, driver should not
program clockgating, dekel firmware will be reponsible for any
clockgating programing.

v2:
Added WARN_ON

v3:
Only calling icl_phy_set_clock_gating() on intel_ddi_pre_enable_hdmi
for GEN11

BSpec issue: 20885
BSpec: 49292

Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Reviewed-by: Matt Roper <matthew.d.roper at intel.com> (v1)
Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
---

Hi Matt, there was 2 small changes since v1, could check and give
another review?

Thanks

 drivers/gpu/drm/i915/display/intel_ddi.c | 57 +++++++-----------------
 1 file changed, 17 insertions(+), 40 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index ebcc7302706b..62a4a8bb2457 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3167,6 +3167,10 @@ icl_phy_set_clock_gating(struct intel_digital_port *dig_port, bool enable)
 	u32 val, bits;
 	int ln;
 
+	/* See "PHY Clockgating programming" note */
+	if (WARN_ON(INTEL_GEN(dev_priv) >= 12))
+		return;
+
 	if (tc_port == PORT_TC_NONE)
 		return;
 
@@ -3175,39 +3179,26 @@ icl_phy_set_clock_gating(struct intel_digital_port *dig_port, bool enable)
 	       MG_DP_MODE_CFG_GAONPWR_GATING;
 
 	for (ln = 0; ln < 2; ln++) {
-		if (INTEL_GEN(dev_priv) >= 12) {
-			I915_WRITE(HIP_INDEX_REG(tc_port), HIP_INDEX_VAL(tc_port, ln));
-			val = I915_READ(DKL_DP_MODE(tc_port));
-		} else {
-			val = I915_READ(MG_DP_MODE(ln, tc_port));
-		}
+		val = I915_READ(MG_DP_MODE(ln, tc_port));
 
 		if (enable)
 			val |= bits;
 		else
 			val &= ~bits;
 
-		if (INTEL_GEN(dev_priv) >= 12)
-			I915_WRITE(DKL_DP_MODE(tc_port), val);
-		else
-			I915_WRITE(MG_DP_MODE(ln, tc_port), val);
+		I915_WRITE(MG_DP_MODE(ln, tc_port), val);
 	}
 
-	if (INTEL_GEN(dev_priv) == 11) {
-		bits = MG_MISC_SUS0_CFG_TR2PWR_GATING |
-		       MG_MISC_SUS0_CFG_CL2PWR_GATING |
-		       MG_MISC_SUS0_CFG_GAONPWR_GATING |
-		       MG_MISC_SUS0_CFG_TRPWR_GATING |
-		       MG_MISC_SUS0_CFG_CL1PWR_GATING |
-		       MG_MISC_SUS0_CFG_DGPWR_GATING;
+	bits = MG_MISC_SUS0_CFG_TR2PWR_GATING | MG_MISC_SUS0_CFG_CL2PWR_GATING |
+	       MG_MISC_SUS0_CFG_GAONPWR_GATING | MG_MISC_SUS0_CFG_TRPWR_GATING |
+	       MG_MISC_SUS0_CFG_CL1PWR_GATING | MG_MISC_SUS0_CFG_DGPWR_GATING;
 
-		val = I915_READ(MG_MISC_SUS0(tc_port));
-		if (enable)
-			val |= (bits | MG_MISC_SUS0_SUSCLK_DYNCLKGATE_MODE(3));
-		else
-			val &= ~(bits | MG_MISC_SUS0_SUSCLK_DYNCLKGATE_MODE_MASK);
-		I915_WRITE(MG_MISC_SUS0(tc_port), val);
-	}
+	val = I915_READ(MG_MISC_SUS0(tc_port));
+	if (enable)
+		val |= (bits | MG_MISC_SUS0_SUSCLK_DYNCLKGATE_MODE(3));
+	else
+		val &= ~(bits | MG_MISC_SUS0_SUSCLK_DYNCLKGATE_MODE_MASK);
+	I915_WRITE(MG_MISC_SUS0(tc_port), val);
 }
 
 static void
@@ -3508,12 +3499,6 @@ static void tgl_ddi_pre_enable_dp(struct intel_encoder *encoder,
 	 * down this function.
 	 */
 
-	/*
-	 * 7.d Type C with DP alternate or fixed/legacy/static connection -
-	 * Disable PHY clock gating per Type-C DDI Buffer page
-	 */
-	icl_phy_set_clock_gating(dig_port, false);
-
 	/* 7.e Configure voltage swing and related IO settings */
 	tgl_ddi_vswing_sequence(encoder, crtc_state->port_clock, level,
 				encoder->type);
@@ -3565,15 +3550,6 @@ static void tgl_ddi_pre_enable_dp(struct intel_encoder *encoder,
 	if (!is_trans_port_sync_mode(crtc_state))
 		intel_dp_stop_link_train(intel_dp);
 
-	/*
-	 * TODO: enable clock gating
-	 *
-	 * It is not written in DP enabling sequence but "PHY Clockgating
-	 * programming" states that clock gating should be enabled after the
-	 * link training but doing so causes all the following trainings to fail
-	 * so not enabling it for now.
-	 */
-
 	/* 7.l Configure and enable FEC if needed */
 	intel_ddi_enable_fec(encoder, crtc_state);
 	intel_dsc_enable(encoder, crtc_state);
@@ -3701,7 +3677,8 @@ static void intel_ddi_pre_enable_hdmi(struct intel_encoder *encoder,
 	else
 		intel_prepare_hdmi_ddi_buffers(encoder, level);
 
-	icl_phy_set_clock_gating(dig_port, true);
+	if (INTEL_GEN(dev_priv) == 11)
+		icl_phy_set_clock_gating(dig_port, true);
 
 	if (IS_GEN9_BC(dev_priv))
 		skl_ddi_set_iboost(encoder, level, INTEL_OUTPUT_HDMI);
-- 
2.24.0