[PATCH] drm/i915/psr: Calculate needed wake lines

[Jouni Högander]

Currently we are using hardcoded 7 for io wake lines and fastwake
lines.

According to bspec io wake time is 42 us and fast wake time
is 42 us for DISPLAY_VER >= 12 and 50 and 32 for older.

Calculate line counts for these and configure PSR2_CTL accordingly

Use 45 us for the fast wake calculation as 42 seems to be too
tight.

Bspec: 49274, 4289

Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  2 +
 drivers/gpu/drm/i915/display/intel_psr.c      | 62 ++++++++++++++-----
 2 files changed, 47 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 9ccae7a46020..654d8401d8eb 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1642,6 +1642,8 @@ struct intel_psr {
 	u16 su_y_granularity;
 	u32 dc3co_exitline;
 	u32 dc3co_exit_delay;
+	u8 io_wake_lines;
+	u8 fast_wake_lines;
 	struct delayed_work dc3co_work;
 };
 
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 2954759e9d12..c355ee2f8c9f 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -542,6 +542,14 @@ static void hsw_activate_psr2(struct intel_dp *intel_dp)
 	val |= EDP_PSR2_FRAME_BEFORE_SU(max_t(u8, intel_dp->psr.sink_sync_latency + 1, 2));
 	val |= intel_psr2_get_tp_time(intel_dp);
 
+	if (DISPLAY_VER(dev_priv) >= 12) {
+		if (intel_dp->psr.io_wake_lines < 9 &&
+		    intel_dp->psr.fast_wake_lines < 9)
+			val |= TGL_EDP_PSR2_BLOCK_COUNT_NUM_2;
+		else
+			val |= TGL_EDP_PSR2_BLOCK_COUNT_NUM_3;
+	}
+
 	/* Wa_22012278275:adl-p */
 	if (IS_ADLP_DISPLAY_STEP(dev_priv, STEP_A0, STEP_E0)) {
 		static const u8 map[] = {
@@ -558,31 +566,21 @@ static void hsw_activate_psr2(struct intel_dp *intel_dp)
 		 * Still using the default IO_BUFFER_WAKE and FAST_WAKE, see
 		 * comments bellow for more information
 		 */
-		u32 tmp, lines = 7;
-
-		val |= TGL_EDP_PSR2_BLOCK_COUNT_NUM_2;
+		u32 tmp;
 
-		tmp = map[lines - TGL_EDP_PSR2_IO_BUFFER_WAKE_MIN_LINES];
+		tmp = map[intel_dp->psr.io_wake_lines - TGL_EDP_PSR2_IO_BUFFER_WAKE_MIN_LINES];
 		tmp = tmp << TGL_EDP_PSR2_IO_BUFFER_WAKE_SHIFT;
 		val |= tmp;
 
-		tmp = map[lines - TGL_EDP_PSR2_FAST_WAKE_MIN_LINES];
+		tmp = map[intel_dp->psr.fast_wake_lines - TGL_EDP_PSR2_FAST_WAKE_MIN_LINES];
 		tmp = tmp << TGL_EDP_PSR2_FAST_WAKE_MIN_SHIFT;
 		val |= tmp;
 	} else if (DISPLAY_VER(dev_priv) >= 12) {
-		/*
-		 * TODO: 7 lines of IO_BUFFER_WAKE and FAST_WAKE are default
-		 * values from BSpec. In order to setting an optimal power
-		 * consumption, lower than 4k resolution mode needs to decrease
-		 * IO_BUFFER_WAKE and FAST_WAKE. And higher than 4K resolution
-		 * mode needs to increase IO_BUFFER_WAKE and FAST_WAKE.
-		 */
-		val |= TGL_EDP_PSR2_BLOCK_COUNT_NUM_2;
-		val |= TGL_EDP_PSR2_IO_BUFFER_WAKE(7);
-		val |= TGL_EDP_PSR2_FAST_WAKE(7);
+		val |= TGL_EDP_PSR2_IO_BUFFER_WAKE(intel_dp->psr.io_wake_lines);
+		val |= TGL_EDP_PSR2_FAST_WAKE(intel_dp->psr.fast_wake_lines);
 	} else if (DISPLAY_VER(dev_priv) >= 9) {
-		val |= EDP_PSR2_IO_BUFFER_WAKE(7);
-		val |= EDP_PSR2_FAST_WAKE(7);
+		val |= EDP_PSR2_IO_BUFFER_WAKE(intel_dp->psr.io_wake_lines);
+		val |= EDP_PSR2_FAST_WAKE(intel_dp->psr.fast_wake_lines);
 	}
 
 	if (intel_dp->psr.req_psr2_sdp_prior_scanline)
@@ -829,6 +827,30 @@ static bool _compute_psr2_sdp_prior_scanline_indication(struct intel_dp *intel_d
 	return true;
 }
 
+static bool _compute_psr2_wake_times(struct intel_dp *intel_dp,
+				     struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+	int io_wake_lines, fast_wake_lines;
+
+	if (DISPLAY_VER(i915) >= 12) {
+		io_wake_lines = intel_usecs_to_scanlines(&crtc_state->uapi.adjusted_mode, 42);
+		fast_wake_lines = intel_usecs_to_scanlines(&crtc_state->uapi.adjusted_mode, 45);
+		if (io_wake_lines > 12 || fast_wake_lines > 12)
+			return false;
+	} else {
+		io_wake_lines = intel_usecs_to_scanlines(&crtc_state->uapi.adjusted_mode, 50);
+		io_wake_lines = intel_usecs_to_scanlines(&crtc_state->uapi.adjusted_mode, 32);
+		if (io_wake_lines > 8 || fast_wake_lines > 8)
+			return false;
+	}
+
+	intel_dp->psr.io_wake_lines = max(io_wake_lines, 7);
+	intel_dp->psr.fast_wake_lines = max(fast_wake_lines, 7);
+
+	return true;
+}
+
 static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
 				    struct intel_crtc_state *crtc_state)
 {
@@ -923,6 +945,12 @@ static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
 		return false;
 	}
 
+	if (!_compute_psr2_wake_times(intel_dp, crtc_state)) {
+		drm_dbg_kms(&dev_priv->drm,
+			    "PSR2 not enabled, Unable to use long enough wake times\n");
+		return false;
+	}
+
 	if (HAS_PSR2_SEL_FETCH(dev_priv)) {
 		if (!intel_psr2_sel_fetch_config_valid(intel_dp, crtc_state) &&
 		    !HAS_PSR_HW_TRACKING(dev_priv)) {
-- 
2.34.1