[PATCH 1/2] drm/i915/display: Refactor handling of dpkgc latency programming

Suraj Kandpal suraj.kandpal at intel.com
Fri Nov 15 03:01:52 UTC 2024


- We want to make sure we have all the required values specially
linetime which is computed after intel_wm_compute, this will also
help implement some WA's which require linetime.
-We do not want to write into any registers during compute_config phase
While we are at it do some more refactors in the function like:
-Use intel_display wherever possible
-Move away from using enable_dpkgc bool and call it fixed_refresh_rate
-Optimize value prepration

--v2
-No need to save anything in intel_display structure [Vinod]
-Move computation and writing into register to intel_atomic_commit_tail
[Vinod]

--v3
-Rename the subject [Vinod]
-Rearrange the variable initialization and declaration [Vinod]
-Reaarange condition evaluation for fixed_refresh_rate [Vinod]

Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c |  2 +
 drivers/gpu/drm/i915/display/intel_wm.c      | 57 ++++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_wm.h      |  2 +
 drivers/gpu/drm/i915/display/skl_watermark.c | 52 ------------------
 4 files changed, 61 insertions(+), 52 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index e790a2de5b3d..4f8e45a794bb 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -7826,6 +7826,8 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
 	dev_priv->display.funcs.display->commit_modeset_enables(state);
 
+	intel_program_dpkgc_latency(state, dev_priv);
+
 	if (state->modeset)
 		intel_set_cdclk_post_plane_update(state);
 
diff --git a/drivers/gpu/drm/i915/display/intel_wm.c b/drivers/gpu/drm/i915/display/intel_wm.c
index d7dc49aecd27..d893403ff611 100644
--- a/drivers/gpu/drm/i915/display/intel_wm.c
+++ b/drivers/gpu/drm/i915/display/intel_wm.c
@@ -7,9 +7,18 @@
 
 #include "i915_drv.h"
 #include "i9xx_wm.h"
+#include "intel_de.h"
 #include "intel_display_types.h"
 #include "intel_wm.h"
 #include "skl_watermark.h"
+#include "skl_watermark_regs.h"
+
+/*
+ * It is expected that DSB can do posted writes to every register in
+ * the pipe and planes within 100us. For flip queue use case, the
+ * recommended DSB execution time is 100us + one SAGV block time.
+ */
+#define DSB_EXE_TIME 100
 
 /**
  * intel_update_watermarks - update FIFO watermark values based on current modes
@@ -131,6 +140,54 @@ bool intel_wm_plane_visible(const struct intel_crtc_state *crtc_state,
 		return plane_state->uapi.visible;
 }
 
+/*
+ * If Fixed Refresh Rate or For VRR case Vmin = Vmax = Flipline:
+ * Program DEEP PKG_C_LATENCY Pkg C with highest valid latency from
+ * watermark level1 and up and above. If watermark level 1 is
+ * invalid program it with all 1's.
+ * Program PKG_C_LATENCY Added Wake Time = DSB execution time
+ * If Variable Refresh Rate where Vmin != Vmax != Flipline:
+ * Program DEEP PKG_C_LATENCY Pkg C with all 1's.
+ * Program PKG_C_LATENCY Added Wake Time = 0
+ */
+void
+intel_program_dpkgc_latency(struct intel_atomic_state *state,
+			    struct drm_i915_private *i915)
+{
+	struct intel_display *display = to_intel_display(state);
+	struct intel_crtc *crtc;
+	struct intel_crtc_state *new_crtc_state;
+	u32 max_latency = LNL_PKG_C_LATENCY_MASK;
+	u32 added_waketime = 0;
+	bool fixed_refresh_rate = false;
+	u32 clear, val;
+	int i;
+
+	if (DISPLAY_VER(display) < 20)
+		return;
+
+	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
+		if (!new_crtc_state->vrr.enable ||
+		    (new_crtc_state->vrr.vmin == new_crtc_state->vrr.vmax &&
+		     new_crtc_state->vrr.vmin == new_crtc_state->vrr.flipline))
+			fixed_refresh_rate = true;
+	}
+
+	if (fixed_refresh_rate) {
+		max_latency = skl_watermark_max_latency(i915, 1);
+		if (max_latency == 0)
+			max_latency = LNL_PKG_C_LATENCY_MASK;
+		added_waketime = DSB_EXE_TIME +
+			display->sagv.block_time_us;
+	}
+
+	clear = LNL_ADDED_WAKE_TIME_MASK | LNL_PKG_C_LATENCY_MASK;
+	val = REG_FIELD_PREP(LNL_PKG_C_LATENCY_MASK, max_latency) |
+		REG_FIELD_PREP(LNL_ADDED_WAKE_TIME_MASK, added_waketime);
+
+	intel_de_rmw(display, LNL_PKG_C_LATENCY, clear, val);
+}
+
 void intel_print_wm_latency(struct drm_i915_private *dev_priv,
 			    const char *name, const u16 wm[])
 {
diff --git a/drivers/gpu/drm/i915/display/intel_wm.h b/drivers/gpu/drm/i915/display/intel_wm.h
index e97cdca89a5c..f47e1354605d 100644
--- a/drivers/gpu/drm/i915/display/intel_wm.h
+++ b/drivers/gpu/drm/i915/display/intel_wm.h
@@ -31,5 +31,7 @@ void intel_print_wm_latency(struct drm_i915_private *i915,
 			    const char *name, const u16 wm[]);
 void intel_wm_init(struct drm_i915_private *i915);
 void intel_wm_debugfs_register(struct drm_i915_private *i915);
+void intel_program_dpkgc_latency(struct intel_atomic_state *state,
+				 struct drm_i915_private *i915);
 
 #endif /* __INTEL_WM_H__ */
diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c
index 1a4c1fa24820..d419edb196c6 100644
--- a/drivers/gpu/drm/i915/display/skl_watermark.c
+++ b/drivers/gpu/drm/i915/display/skl_watermark.c
@@ -28,12 +28,6 @@
 #include "skl_watermark.h"
 #include "skl_watermark_regs.h"
 
-/*It is expected that DSB can do posted writes to every register in
- * the pipe and planes within 100us. For flip queue use case, the
- * recommended DSB execution time is 100us + one SAGV block time.
- */
-#define DSB_EXE_TIME 100
-
 static void skl_sagv_disable(struct drm_i915_private *i915);
 
 /* Stores plane specific WM parameters */
@@ -2844,51 +2838,12 @@ static int skl_wm_add_affected_planes(struct intel_atomic_state *state,
 	return 0;
 }
 
-/*
- * If Fixed Refresh Rate or For VRR case Vmin = Vmax = Flipline:
- * Program DEEP PKG_C_LATENCY Pkg C with highest valid latency from
- * watermark level1 and up and above. If watermark level 1 is
- * invalid program it with all 1's.
- * Program PKG_C_LATENCY Added Wake Time = DSB execution time
- * If Variable Refresh Rate where Vmin != Vmax != Flipline:
- * Program DEEP PKG_C_LATENCY Pkg C with all 1's.
- * Program PKG_C_LATENCY Added Wake Time = 0
- */
-static void
-skl_program_dpkgc_latency(struct drm_i915_private *i915, bool enable_dpkgc)
-{
-	u32 max_latency = 0;
-	u32 clear = 0, val = 0;
-	u32 added_wake_time = 0;
-
-	if (DISPLAY_VER(i915) < 20)
-		return;
-
-	if (enable_dpkgc) {
-		max_latency = skl_watermark_max_latency(i915, 1);
-		if (max_latency == 0)
-			max_latency = LNL_PKG_C_LATENCY_MASK;
-		added_wake_time = DSB_EXE_TIME +
-			i915->display.sagv.block_time_us;
-	} else {
-		max_latency = LNL_PKG_C_LATENCY_MASK;
-		added_wake_time = 0;
-	}
-
-	clear |= LNL_ADDED_WAKE_TIME_MASK | LNL_PKG_C_LATENCY_MASK;
-	val |= REG_FIELD_PREP(LNL_PKG_C_LATENCY_MASK, max_latency);
-	val |= REG_FIELD_PREP(LNL_ADDED_WAKE_TIME_MASK, added_wake_time);
-
-	intel_uncore_rmw(&i915->uncore, LNL_PKG_C_LATENCY, clear, val);
-}
-
 static int
 skl_compute_wm(struct intel_atomic_state *state)
 {
 	struct intel_crtc *crtc;
 	struct intel_crtc_state __maybe_unused *new_crtc_state;
 	int ret, i;
-	bool enable_dpkgc = false;
 
 	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
 		ret = skl_build_pipe_wm(state, crtc);
@@ -2913,15 +2868,8 @@ skl_compute_wm(struct intel_atomic_state *state)
 		ret = skl_wm_add_affected_planes(state, crtc);
 		if (ret)
 			return ret;
-
-		if ((new_crtc_state->vrr.vmin == new_crtc_state->vrr.vmax &&
-		     new_crtc_state->vrr.vmin == new_crtc_state->vrr.flipline) ||
-		    !new_crtc_state->vrr.enable)
-			enable_dpkgc = true;
 	}
 
-	skl_program_dpkgc_latency(to_i915(state->base.dev), enable_dpkgc);
-
 	skl_print_wm_changes(state);
 
 	return 0;
-- 
2.34.1



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