drm/i915/psr: Try to program link training times correctly

The default of 0 is 500us of link training, but that's not enough for
some platforms. Decoding this correctly means we're using 2.5ms of
link training on these platforms, which fixes flickering issues
associated with enabling PSR.

v2: Unbotch the math a bit.

v3: Drop debug hunk.

v4: Improve commit message.

Tested-by: Lyude <cpaul@redhat.com>
Cc: Lyude <cpaul@redhat.com>
Cc: stable@vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95176
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Sonika Jindal <sonika.jindal@intel.com>
Cc: Durgadoss R <durgadoss.r@intel.com>
Cc: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: fritsch@kodi.tv
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463590036-17824-2-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/i915/intel_psr.c

@@ -280,22 +280,61 @@ static void hsw_psr_enable_source(struct intel_dp *intel_dp)
 	 * with the 5 or 6 idle patterns.
 	 */
 	uint32_t idle_frames = max(6, dev_priv->vbt.psr.idle_frames);
-	uint32_t val = 0x0;
+	uint32_t val = EDP_PSR_ENABLE;
+
+	val |= max_sleep_time << EDP_PSR_MAX_SLEEP_TIME_SHIFT;
+	val |= idle_frames << EDP_PSR_IDLE_FRAME_SHIFT;
 
 	if (IS_HASWELL(dev))
 		val |= EDP_PSR_MIN_LINK_ENTRY_TIME_8_LINES;
 
 	if (dev_priv->psr.link_standby)
 		val |= EDP_PSR_LINK_STANDBY;
 
-	I915_WRITE(EDP_PSR_CTL, val |
-		   max_sleep_time << EDP_PSR_MAX_SLEEP_TIME_SHIFT |
-		   idle_frames << EDP_PSR_IDLE_FRAME_SHIFT |
-		   EDP_PSR_ENABLE);
+	if (dev_priv->vbt.psr.tp1_wakeup_time > 5)
+		val |= EDP_PSR_TP1_TIME_2500us;
+	else if (dev_priv->vbt.psr.tp1_wakeup_time > 1)
+		val |= EDP_PSR_TP1_TIME_500us;
+	else if (dev_priv->vbt.psr.tp1_wakeup_time > 0)
+		val |= EDP_PSR_TP1_TIME_100us;
+	else
+		val |= EDP_PSR_TP1_TIME_0us;
+
+	if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 5)
+		val |= EDP_PSR_TP2_TP3_TIME_2500us;
+	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 1)
+		val |= EDP_PSR_TP2_TP3_TIME_500us;
+	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 0)
+		val |= EDP_PSR_TP2_TP3_TIME_100us;
+	else
+		val |= EDP_PSR_TP2_TP3_TIME_0us;
+
+	if (intel_dp_source_supports_hbr2(intel_dp) &&
+	    drm_dp_tps3_supported(intel_dp->dpcd))
+		val |= EDP_PSR_TP1_TP3_SEL;
+	else
+		val |= EDP_PSR_TP1_TP2_SEL;
+
+	I915_WRITE(EDP_PSR_CTL, val);
+
+	if (!dev_priv->psr.psr2_support)
+		return;
+
+	/* FIXME: selective update is probably totally broken because it doesn't
+	 * mesh at all with our frontbuffer tracking. And the hw alone isn't
+	 * good enough. */
+	val = EDP_PSR2_ENABLE | EDP_SU_TRACK_ENABLE;
+
+	if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 5)
+		val |= EDP_PSR2_TP2_TIME_2500;
+	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 1)
+		val |= EDP_PSR2_TP2_TIME_500;
+	else if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 0)
+		val |= EDP_PSR2_TP2_TIME_100;
+	else
+		val |= EDP_PSR2_TP2_TIME_50;
 
-	if (dev_priv->psr.psr2_support)
-		I915_WRITE(EDP_PSR2_CTL, EDP_PSR2_ENABLE |
-				EDP_SU_TRACK_ENABLE | EDP_PSR2_TP2_TIME_100);
+	I915_WRITE(EDP_PSR2_CTL, val);
 }
 
 static bool intel_psr_match_conditions(struct intel_dp *intel_dp)