drm/i915/psr: Use calculated io and fast wake lines

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

According to Bspec io and fast wake times are both 42us for
DISPLAY_VER >= 12 and 50us and 32us for older platforms.

Calculate line counts for these and configure them into PSR2_CTL
accordingly

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

Bspec: 49274, 4289

Cc: Mika Kahola <[email protected]>
Cc: José Roberto de Souza <[email protected]>
Fixes: 64cf40a ("drm/i915/psr: Program default IO buffer Wake and Fast Wake")
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/7725
Signed-off-by: Jouni Högander <[email protected]>
Reviewed-by: Stanislav Lisovskiy <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
(cherry picked from commit cb42e8e)
Signed-off-by: Jani Nikula <[email protected]>

Author: hogander

drivers/gpu/drm/i915/display/intel_display_types.h

@@ -1631,6 +1631,8 @@ struct intel_psr {
 	bool psr2_sel_fetch_cff_enabled;
 	bool req_psr2_sdp_prior_scanline;
 	u8 sink_sync_latency;
+	u8 io_wake_lines;
+	u8 fast_wake_lines;
 	ktime_t last_entry_attempt;
 	ktime_t last_exit;
 	bool sink_not_reliable;

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)
@@ -842,6 +840,46 @@ 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, io_wake_time, fast_wake_lines, fast_wake_time;
+	u8 max_wake_lines;
+
+	if (DISPLAY_VER(i915) >= 12) {
+		io_wake_time = 42;
+		/*
+		 * According to Bspec it's 42us, but based on testing
+		 * it is not enough -> use 45 us.
+		 */
+		fast_wake_time = 45;
+		max_wake_lines = 12;
+	} else {
+		io_wake_time = 50;
+		fast_wake_time = 32;
+		max_wake_lines = 8;
+	}
+
+	io_wake_lines = intel_usecs_to_scanlines(
+		&crtc_state->uapi.adjusted_mode, io_wake_time);
+	fast_wake_lines = intel_usecs_to_scanlines(
+		&crtc_state->uapi.adjusted_mode, fast_wake_time);
+
+	if (io_wake_lines > max_wake_lines ||
+	    fast_wake_lines > max_wake_lines)
+		return false;
+
+	if (i915->params.psr_safest_params)
+		io_wake_lines = fast_wake_lines = max_wake_lines;
+
+	/* According to Bspec lower limit should be set as 7 lines. */
+	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)
 {
@@ -936,6 +974,12 @@ 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)) {