[PATCH 2/2] drm/i915/watermark: Modify latency programmed into PKG_C_LATENCY

[Suraj Kandpal <suraj.kandpal@xxxxxxxxx>]

Increase the latency programmed into PKG_C_LATENCY latency to be
a multiple of line time which is written into WM_LINETIME.

--v2
-Fix commit subject line [Sai Teja]
-Use individual DISPLAY_VER checks instead of range [Sai Teja]
-Initialize max_linetime [Sai Teja]

--v3
-take into account the scenario when adjusted_latency is 0 [Vinod]

--v4
-rename adjusted_latency to latency [Mitul]
-fix the condition in which dpkgc is disabled [Vinod]

--v5
-Add check to see if max_linetime is 0 [Vinod]

WA: 22020299601
Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
---
 drivers/gpu/drm/i915/display/intel_wm.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_wm.c b/drivers/gpu/drm/i915/display/intel_wm.c
index 620873d1244f..ce11a69b36cc 100644
--- a/drivers/gpu/drm/i915/display/intel_wm.c
+++ b/drivers/gpu/drm/i915/display/intel_wm.c
@@ -157,9 +157,10 @@ intel_program_dpkgc_latency(struct intel_atomic_state *state,
 	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 latency = LNL_PKG_C_LATENCY_MASK;
 	u32 clear = 0, val = 0;
 	u32 added_waketime = 0;
+	u32 max_linetime = 0;
 	int i;
 	bool fixed_refresh_rate = false;
 
@@ -171,18 +172,29 @@ intel_program_dpkgc_latency(struct intel_atomic_state *state,
 		     new_crtc_state->vrr.vmin == new_crtc_state->vrr.flipline) ||
 		    !new_crtc_state->vrr.enable)
 			fixed_refresh_rate = true;
+
+		max_linetime = max(new_crtc_state->linetime, max_linetime);
 	}
 
 	if (fixed_refresh_rate) {
-		max_latency = skl_watermark_max_latency(i915, 1);
-		if (max_latency == 0)
-			max_latency = LNL_PKG_C_LATENCY_MASK;
+		latency = skl_watermark_max_latency(i915, 1);
+
+		/* Wa_22020299601 */
+		if (latency) {
+			if ((DISPLAY_VER(display) == 20 || DISPLAY_VER(display) == 30) &&
+			    max_linetime)
+				latency = max_linetime *
+					DIV_ROUND_UP(latency, max_linetime);
+		} else {
+			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) |
+	val |= REG_FIELD_PREP(LNL_PKG_C_LATENCY_MASK, latency) |
 		REG_FIELD_PREP(LNL_ADDED_WAKE_TIME_MASK, added_waketime);
 
 	intel_de_rmw(display, LNL_PKG_C_LATENCY, clear, val);
-- 
2.34.1