drm/i915/psr: fix blank screen issue for psr2

Psr1 and psr2 are mutually exclusive,ie when psr2 is enabled,
psr1 should be disabled.When psr2 is exited , bit 31 of reg
PSR2_CTL must be set to 0 but currently bit 31 of SRD_CTL
(psr1 control register)is set to 0.
Also ,PSR2_IDLE state is looked up from SRD_STATUS(psr1 register)
instead of PSR2_STATUS register, which has wrong data, resulting
in blankscreen.
hsw_enable_source is split into hsw_enable_source_psr1 and
hsw_enable_source_psr2 for easier code review and maintenance,
as suggested by rodrigo and jim.

v2: (Rodrigo)
- Rename hsw_enable_source_psr* to intel_enable_source_psr*

v3: (Rodrigo)
- In hsw_psr_disable ,
  1) for psr active case, handle psr2 followed by psr1.
  2) psr inactive case, handle psr2 followed by psr1

v4:(Rodrigo)
- move psr2 restriction(32X20) to match_conditions function
  returning false and fully blocking PSR to a new patch before
  this one.

v5: in source_psr2, removed val = EDP_PSR_ENABLE

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jim Bride <jim.bride@linux.intel.com>
Signed-off-by: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
Signed-off-by: Patil Deepti <deepti.patil@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1484244059-9201-1-git-send-email-vathsala.nagaraju@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -3615,6 +3615,9 @@ enum {
 #define   EDP_PSR2_FRAME_BEFORE_SU_MASK	(0xf<<4)
 #define   EDP_PSR2_IDLE_MASK		0xf
 
+#define EDP_PSR2_STATUS_CTL            _MMIO(0x6f940)
+#define EDP_PSR2_STATUS_STATE_MASK     (0xf<<28)
+
 /* VGA port control */
 #define ADPA			_MMIO(0x61100)
 #define PCH_ADPA                _MMIO(0xe1100)

drivers/gpu/drm/i915/intel_psr.c

@@ -261,7 +261,7 @@ static void vlv_psr_activate(struct intel_dp *intel_dp)
 		   VLV_EDP_PSR_ACTIVE_ENTRY);
 }
 
-static void hsw_psr_enable_source(struct intel_dp *intel_dp)
+static void intel_enable_source_psr1(struct intel_dp *intel_dp)
 {
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
 	struct drm_device *dev = dig_port->base.base.dev;
@@ -312,14 +312,29 @@ static void hsw_psr_enable_source(struct intel_dp *intel_dp)
 		val |= EDP_PSR_TP1_TP2_SEL;
 
 	I915_WRITE(EDP_PSR_CTL, val);
+}
 
-	if (!dev_priv->psr.psr2_support)
-		return;
+static void intel_enable_source_psr2(struct intel_dp *intel_dp)
+{
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	/*
+	 * Let's respect VBT in case VBT asks a higher idle_frame value.
+	 * Let's use 6 as the minimum to cover all known cases including
+	 * the off-by-one issue that HW has in some cases. Also there are
+	 * cases where sink should be able to train
+	 * with the 5 or 6 idle patterns.
+	 */
+	uint32_t idle_frames = max(6, dev_priv->vbt.psr.idle_frames);
+	uint32_t val;
+
+	val = idle_frames << EDP_PSR_IDLE_FRAME_SHIFT;
 
 	/* 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;
+	val |= EDP_PSR2_ENABLE | EDP_SU_TRACK_ENABLE;
 
 	if (dev_priv->vbt.psr.tp2_tp3_wakeup_time > 5)
 		val |= EDP_PSR2_TP2_TIME_2500;
@@ -333,6 +348,19 @@ static void hsw_psr_enable_source(struct intel_dp *intel_dp)
 	I915_WRITE(EDP_PSR2_CTL, val);
 }
 
+static void hsw_psr_enable_source(struct intel_dp *intel_dp)
+{
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+
+	/* psr1 and psr2 are mutually exclusive.*/
+	if (dev_priv->psr.psr2_support)
+		intel_enable_source_psr2(intel_dp);
+	else
+		intel_enable_source_psr1(intel_dp);
+}
+
 static bool intel_psr_match_conditions(struct intel_dp *intel_dp)
 {
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
@@ -417,6 +445,9 @@ static void intel_psr_activate(struct intel_dp *intel_dp)
 	struct drm_device *dev = intel_dig_port->base.base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
 
+	if (dev_priv->psr.psr2_support)
+		WARN_ON(I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE);
+	else
 		WARN_ON(I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE);
 	WARN_ON(dev_priv->psr.active);
 	lockdep_assert_held(&dev_priv->psr.lock);
@@ -468,10 +499,11 @@ void intel_psr_enable(struct intel_dp *intel_dp)
 	dev_priv->psr.busy_frontbuffer_bits = 0;
 
 	if (HAS_DDI(dev_priv)) {
-		hsw_psr_setup_vsc(intel_dp);
-
 		if (dev_priv->psr.psr2_support) {
 			skl_psr_setup_su_vsc(intel_dp);
+		} else {
+			/* set up vsc header for psr1 */
+			hsw_psr_setup_vsc(intel_dp);
 		}
 
 		/*
@@ -558,19 +590,34 @@ static void hsw_psr_disable(struct intel_dp *intel_dp)
 	struct drm_i915_private *dev_priv = to_i915(dev);
 
 	if (dev_priv->psr.active) {
+		if (dev_priv->psr.psr2_support) {
+			I915_WRITE(EDP_PSR2_CTL,
+				I915_READ(EDP_PSR2_CTL) &
+					~(EDP_PSR2_ENABLE |
+					EDP_SU_TRACK_ENABLE));
+			/* Wait till PSR2 is idle */
+			if (intel_wait_for_register(dev_priv,
+						    EDP_PSR2_STATUS_CTL,
+						    EDP_PSR2_STATUS_STATE_MASK,
+						    0,
+						    2000))
+			DRM_ERROR("Timed out waiting for PSR2 Idle State\n");
+		} else {
 			I915_WRITE(EDP_PSR_CTL,
 				   I915_READ(EDP_PSR_CTL) & ~EDP_PSR_ENABLE);
-
-		/* Wait till PSR is idle */
+			/* Wait till PSR1 is idle */
 			if (intel_wait_for_register(dev_priv,
 						    EDP_PSR_STATUS_CTL,
 						    EDP_PSR_STATUS_STATE_MASK,
 						    0,
 						    2000))
 			DRM_ERROR("Timed out waiting for PSR Idle State\n");
-
+		}
 		dev_priv->psr.active = false;
 	} else {
+		if (dev_priv->psr.psr2_support)
+			WARN_ON(I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE);
+		else
 			WARN_ON(I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE);
 	}
 }
@@ -622,6 +669,16 @@ static void intel_psr_work(struct work_struct *work)
 	 * and be ready for re-enable.
 	 */
 	if (HAS_DDI(dev_priv)) {
+		if (dev_priv->psr.psr2_support) {
+			if (intel_wait_for_register(dev_priv,
+						EDP_PSR2_STATUS_CTL,
+						EDP_PSR2_STATUS_STATE_MASK,
+						0,
+						50)) {
+				DRM_ERROR("Timed out waiting for PSR2 Idle for re-enable\n");
+				return;
+			}
+		} else {
 			if (intel_wait_for_register(dev_priv,
 						EDP_PSR_STATUS_CTL,
 						EDP_PSR_STATUS_STATE_MASK,
@@ -630,6 +687,7 @@ static void intel_psr_work(struct work_struct *work)
 				DRM_ERROR("Timed out waiting for PSR Idle for re-enable\n");
 				return;
 			}
+		}
 	} else {
 		if (intel_wait_for_register(dev_priv,
 					    VLV_PSRSTAT(pipe),
@@ -670,11 +728,15 @@ static void intel_psr_exit(struct drm_i915_private *dev_priv)
 		return;
 
 	if (HAS_DDI(dev_priv)) {
+		if (dev_priv->psr.psr2_support) {
+			val = I915_READ(EDP_PSR2_CTL);
+			WARN_ON(!(val & EDP_PSR2_ENABLE));
+			I915_WRITE(EDP_PSR2_CTL, val & ~EDP_PSR2_ENABLE);
+		} else {
 			val = I915_READ(EDP_PSR_CTL);
-
 			WARN_ON(!(val & EDP_PSR_ENABLE));
-
 			I915_WRITE(EDP_PSR_CTL, val & ~EDP_PSR_ENABLE);
+		}
 	} else {
 		val = I915_READ(VLV_PSRCTL(pipe));