[Intel-gfx] [RFCv2 DP-typeC 2/6] drm/i915/dp: Reuse shared DPLL if it exists already

[Durgadoss R]

Do not call intel_get_shared_dpll() if there exists a
valid shared DPLL already.

Signed-off-by: Durgadoss R <durgadoss.r at intel.com>
---
 drivers/gpu/drm/i915/intel_ddi.c     | 70 ++++++++++++++++++++----------------
 drivers/gpu/drm/i915/intel_display.c |  2 +-
 drivers/gpu/drm/i915/intel_drv.h     |  2 +-
 3 files changed, 42 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 9098c12..8e4ea36 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1258,7 +1258,8 @@ hsw_ddi_calculate_wrpll(int clock /* in Hz */,
 static bool
 hsw_ddi_pll_select(struct intel_crtc *intel_crtc,
 		   struct intel_crtc_state *crtc_state,
-		   struct intel_encoder *intel_encoder)
+		   struct intel_encoder *intel_encoder,
+		   bool find_dpll)
 {
 	int clock = crtc_state->port_clock;
 
@@ -1278,14 +1279,16 @@ hsw_ddi_pll_select(struct intel_crtc *intel_crtc,
 
 		crtc_state->dpll_hw_state.wrpll = val;
 
-		pll = intel_get_shared_dpll(intel_crtc, crtc_state);
-		if (pll == NULL) {
-			DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
-					 pipe_name(intel_crtc->pipe));
-			return false;
-		}
+		if (find_dpll) {
+			pll = intel_get_shared_dpll(intel_crtc, crtc_state);
+			if (pll == NULL) {
+				DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
+						 pipe_name(intel_crtc->pipe));
+				return false;
+			}
 
-		crtc_state->ddi_pll_sel = PORT_CLK_SEL_WRPLL(pll->id);
+			crtc_state->ddi_pll_sel = PORT_CLK_SEL_WRPLL(pll->id);
+		}
 	}
 
 	return true;
@@ -1540,7 +1543,8 @@ skip_remaining_dividers:
 static bool
 skl_ddi_pll_select(struct intel_crtc *intel_crtc,
 		   struct intel_crtc_state *crtc_state,
-		   struct intel_encoder *intel_encoder)
+		   struct intel_encoder *intel_encoder,
+		   bool find_dpll)
 {
 	struct intel_shared_dpll *pll;
 	uint32_t ctrl1, cfgcr1, cfgcr2;
@@ -1594,15 +1598,17 @@ skl_ddi_pll_select(struct intel_crtc *intel_crtc,
 	crtc_state->dpll_hw_state.cfgcr1 = cfgcr1;
 	crtc_state->dpll_hw_state.cfgcr2 = cfgcr2;
 
-	pll = intel_get_shared_dpll(intel_crtc, crtc_state);
-	if (pll == NULL) {
-		DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
-				 pipe_name(intel_crtc->pipe));
-		return false;
-	}
+	if (find_dpll) {
+		pll = intel_get_shared_dpll(intel_crtc, crtc_state);
+		if (pll == NULL) {
+			DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
+					 pipe_name(intel_crtc->pipe));
+			return false;
+		}
 
-	/* shared DPLL id 0 is DPLL 1 */
-	crtc_state->ddi_pll_sel = pll->id + 1;
+		/* shared DPLL id 0 is DPLL 1 */
+		crtc_state->ddi_pll_sel = pll->id + 1;
+	}
 
 	return true;
 }
@@ -1632,7 +1638,8 @@ static const struct bxt_clk_div bxt_dp_clk_val[] = {
 static bool
 bxt_ddi_pll_select(struct intel_crtc *intel_crtc,
 		   struct intel_crtc_state *crtc_state,
-		   struct intel_encoder *intel_encoder)
+		   struct intel_encoder *intel_encoder,
+		   bool find_pll)
 {
 	struct intel_shared_dpll *pll;
 	struct bxt_clk_div clk_div = {0};
@@ -1741,15 +1748,17 @@ bxt_ddi_pll_select(struct intel_crtc *intel_crtc,
 	crtc_state->dpll_hw_state.pcsdw12 =
 		LANESTAGGER_STRAP_OVRD | lanestagger;
 
-	pll = intel_get_shared_dpll(intel_crtc, crtc_state);
-	if (pll == NULL) {
-		DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
-			pipe_name(intel_crtc->pipe));
-		return false;
-	}
+	if (find_pll) {
+		pll = intel_get_shared_dpll(intel_crtc, crtc_state);
+		if (pll == NULL) {
+			DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
+				pipe_name(intel_crtc->pipe));
+			return false;
+		}
 
-	/* shared DPLL id 0 is DPLL A */
-	crtc_state->ddi_pll_sel = pll->id;
+		/* shared DPLL id 0 is DPLL A */
+		crtc_state->ddi_pll_sel = pll->id;
+	}
 
 	return true;
 }
@@ -1763,7 +1772,8 @@ bxt_ddi_pll_select(struct intel_crtc *intel_crtc,
  */
 bool intel_ddi_pll_select(struct intel_crtc *intel_crtc,
 			  struct intel_crtc_state *crtc_state,
-			  struct intel_encoder *valid_encoder)
+			  struct intel_encoder *valid_encoder,
+			  bool find_dpll)
 {
 	struct drm_device *dev = intel_crtc->base.dev;
 	struct intel_encoder *intel_encoder;
@@ -1775,13 +1785,13 @@ bool intel_ddi_pll_select(struct intel_crtc *intel_crtc,
 
 	if (IS_SKYLAKE(dev))
 		return skl_ddi_pll_select(intel_crtc, crtc_state,
-					  intel_encoder);
+					  intel_encoder, find_dpll);
 	else if (IS_BROXTON(dev))
 		return bxt_ddi_pll_select(intel_crtc, crtc_state,
-					  intel_encoder);
+					  intel_encoder, find_dpll);
 	else
 		return hsw_ddi_pll_select(intel_crtc, crtc_state,
-					  intel_encoder);
+					  intel_encoder, find_dpll);
 }
 
 void intel_ddi_set_pipe_settings(struct drm_crtc *crtc)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8ae6d7b..5c2b4ce 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9661,7 +9661,7 @@ static void broadwell_modeset_commit_cdclk(struct drm_atomic_state *old_state)
 static int haswell_crtc_compute_clock(struct intel_crtc *crtc,
 				      struct intel_crtc_state *crtc_state)
 {
-	if (!intel_ddi_pll_select(crtc, crtc_state, NULL))
+	if (!intel_ddi_pll_select(crtc, crtc_state, NULL, true))
 		return -EINVAL;
 
 	crtc->lowfreq_avail = false;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 0822ab6..cbcfa14 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -990,7 +990,7 @@ void intel_ddi_enable_pipe_clock(struct intel_crtc *intel_crtc);
 void intel_ddi_disable_pipe_clock(struct intel_crtc *intel_crtc);
 bool intel_ddi_pll_select(struct intel_crtc *crtc,
 			  struct intel_crtc_state *crtc_state,
-			  struct intel_encoder *encoder);
+			  struct intel_encoder *encoder, bool find_dpll);
 void intel_ddi_set_pipe_settings(struct drm_crtc *crtc);
 void intel_ddi_prepare_link_retrain(struct drm_encoder *encoder);
 bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector);
-- 
1.9.1