[Intel-gfx] [PATCH 04/10] drm/i915: PSR VLV/CHV: Introduce setup, enable and disable functions

R, Durgadoss durgadoss.r at intel.com
Thu Nov 6 19:32:44 CET 2014


>-----Original Message-----
>From: Intel-gfx [mailto:intel-gfx-bounces at lists.freedesktop.org] On Behalf Of
>Rodrigo Vivi
>Sent: Wednesday, October 29, 2014 12:16 AM
>To: intel-gfx at lists.freedesktop.org
>Cc: Vivi, Rodrigo
>Subject: [Intel-gfx] [PATCH 04/10] drm/i915: PSR VLV/CHV: Introduce setup,
>enable and disable functions
>
>The biggest difference from HSW/BDW PSR here is that VLV enable_source
>function enables PSR but let it in Inactive state. So it might be called
>on early stage along with setup and enable_sink ones.
>
>Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
>---
> drivers/gpu/drm/i915/intel_dp.c | 161
>++++++++++++++++++++++++++++++++++++----
> 1 file changed, 145 insertions(+), 16 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>index ac70b3a..335a711 100644
>--- a/drivers/gpu/drm/i915/intel_dp.c
>+++ b/drivers/gpu/drm/i915/intel_dp.c
>@@ -2134,7 +2134,44 @@ static void intel_edp_psr_write_vsc(struct intel_dp
>*intel_dp,
> 	POSTING_READ(ctl_reg);
> }
>
>-static void intel_edp_psr_setup_vsc(struct intel_dp *intel_dp)
>+/**
>+ * vlv_edp_psr_setup_vsc - Setup PSR related VSC aux registers on VLV+.
>+ * @intel_dp: DP struct
>+ *
>+ * On VLV we don't need to generate VSC. It auto generates according
>+ * EDP 1.3 spec, Table 3.10.
>+ * HB0   - Secondary Data Packet ID = 0
>+ * HB1   - Secondary Data Packet Type = 07h
>+ * HB2   - Bits 4:0 = Revision Number = 02h
>+ *         Bits 7:5 = Reserved (all 0s)
>+ * HB3   - Bits 4:0 Number of Valid Data Bytes = 08h
>+ *         Bits 7:5 Reserved
>+ * DB0   - Bits 7:4 Stereo Interface Method Specific Paramenter
>+ *         Bits 3:0 Stereo Interface Method Code
>+ * DB1   - Bit 0 - PSR State (0 when Inactive / 1 when Active)
>+ *         Bit 1 - Update RFB. (0 do not update RFB / 1 update RFB)
>+ *         Bit 2 - CRC Valid. VLV always send 0 which
>+ *                            means CRC value in DB7:2 invalid
>+ *         Bits 7:3 - Reserved
>+ * DB2-7 - CRC - don't care because DB1[2] always tells this is invalid.
>+ */
>+static void vlv_edp_psr_setup_vsc(struct intel_dp *intel_dp)
>+{
>+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
>+	struct drm_device *dev = intel_dig_port->base.base.dev;
>+	struct drm_i915_private *dev_priv = dev->dev_private;
>+	struct drm_crtc *crtc = intel_dig_port->base.base.crtc;
>+	enum pipe pipe = to_intel_crtc(crtc)->pipe;
>+	uint32_t val;
>+
>+	/* VLV auto-generate VSC package as per EDP 1.3 spec, Table 3.10 */
>+	val  = I915_READ(VLV_VSCSDP(pipe));
>+	val &= ~VLV_EDP_PSR_SDP_FREQ_MASK;
>+	val |= VLV_EDP_PSR_SDP_FREQ_EVFRAME;
>+	I915_WRITE(VLV_VSCSDP(pipe), val);
>+}
>+
>+static void hsw_edp_psr_setup_vsc(struct intel_dp *intel_dp)
> {
> 	struct edp_vsc_psr psr_vsc;
>
>@@ -2147,7 +2184,20 @@ static void intel_edp_psr_setup_vsc(struct intel_dp
>*intel_dp)
> 	intel_edp_psr_write_vsc(intel_dp, &psr_vsc);
> }
>
>-static void intel_edp_psr_enable_sink(struct intel_dp *intel_dp)
>+/**
>+ * vlv_edp_psr_enable_sink - Enable PSR on Panel for VLV.
>+ * @intel_dp: DP struct
>+ *
>+ * This function enable PSR on Panel (Sink) side over DPCD write.
>+ */
>+static void vlv_edp_psr_enable_sink(struct intel_dp *intel_dp)
>+{
>+	/* Enable PSR in sink */
>+	drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG,
>+			   DP_PSR_ENABLE);
>+}
>+
>+static void hsw_edp_psr_enable_sink(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;
>@@ -2191,7 +2241,28 @@ static void intel_edp_psr_enable_sink(struct intel_dp
>*intel_dp)
> 		   (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT));
> }
>
>-static void intel_edp_psr_enable_source(struct intel_dp *intel_dp)
>+/**
>+ * vlv_edp_psr_enable_source - Enable PSR on VLV without activate it.
>+ * @intel_dp: DP struct
>+ *
>+ * This function do the transition from PSR_state 0 to PSR_state 1 that is
>+ * PSR Inactive one..
>+ */
>+static void vlv_edp_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 = dev->dev_private;
>+	struct drm_crtc *crtc = dig_port->base.base.crtc;
>+	enum pipe pipe = to_intel_crtc(crtc)->pipe;
>+
>+	I915_WRITE(VLV_PSRCTL(pipe),
>+		   VLV_EDP_PSR_SRC_TRANSMITTER_STATE |

I see we are keeping the source active during PSR.
Making this '0' may provide better power savings,
but we need to manage a lot of hassle during PSR exit..
(like Link training, DPIO/PLL bring up etc..)

>+		   VLV_EDP_PSR_MODE_SW_TIMER |
>+		   VLV_EDP_PSR_ENABLE);
>+}
>+
>+static void hsw_edp_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;
>@@ -2276,7 +2347,7 @@ static void intel_edp_psr_do_enable(struct intel_dp
>*intel_dp)
> 	lockdep_assert_held(&dev_priv->psr.lock);
>
> 	/* Enable/Re-enable PSR on the host */
>-	intel_edp_psr_enable_source(intel_dp);
>+	hsw_edp_psr_enable_source(intel_dp);
>
> 	dev_priv->psr.active = true;
> }
>@@ -2307,30 +2378,71 @@ void intel_edp_psr_enable(struct intel_dp *intel_dp)
>
> 	dev_priv->psr.busy_frontbuffer_bits = 0;
>
>-	intel_edp_psr_setup_vsc(intel_dp);
>+	if (HAS_DDI(dev)) {
>+		hsw_edp_psr_setup_vsc(intel_dp);
>+
>+		/* Avoid continuous PSR exit by masking memup and hpd */
>+		I915_WRITE(EDP_PSR_DEBUG_CTL(dev),
>EDP_PSR_DEBUG_MASK_MEMUP |
>+			   EDP_PSR_DEBUG_MASK_HPD |
>EDP_PSR_DEBUG_MASK_LPSP);
>
>-	/* Avoid continuous PSR exit by masking memup and hpd */
>-	I915_WRITE(EDP_PSR_DEBUG_CTL(dev),
>EDP_PSR_DEBUG_MASK_MEMUP |
>-		   EDP_PSR_DEBUG_MASK_HPD | EDP_PSR_DEBUG_MASK_LPSP);
>+		/* Enable PSR on the panel */
>+		hsw_edp_psr_enable_sink(intel_dp);
>+	} else {
>+		vlv_edp_psr_setup_vsc(intel_dp);
>
>-	/* Enable PSR on the panel */
>-	intel_edp_psr_enable_sink(intel_dp);
>+		/* Enable PSR on the panel */
>+		vlv_edp_psr_enable_sink(intel_dp);
>+
>+		/* On HSW/BDW enable_source also means go to PSR entry/active
>+		 * state as soon as idle_frame achieved and here would be
>+		 * to soon. However on VLV enable_source just enable PSR
>+		 * but let it on inactive state. So we might do this prior
>+		 * to active transition, i.e. here.
>+		 */
>+		vlv_edp_psr_enable_source(intel_dp);
>+	}
>
> 	dev_priv->psr.enabled = intel_dp;
> unlock:
> 	mutex_unlock(&dev_priv->psr.lock);
> }
>
>-void intel_edp_psr_disable(struct intel_dp *intel_dp)
>+/**
>+ * vlv_edp_psr_disable - Disable PSR on VLV
>+ * @intel_dp: DP struct
>+ *
>+ * This function puts PSR VLV back to PSR_state 0 that is PSR Disabled.

I hope you meant 'puts VLV PSR'..

>+ */
>+static void vlv_edp_psr_disable(struct intel_dp *intel_dp)
> {
>-	struct drm_device *dev = intel_dp_to_dev(intel_dp);
>+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
>+	struct drm_device *dev = intel_dig_port->base.base.dev;
> 	struct drm_i915_private *dev_priv = dev->dev_private;
>+	struct intel_crtc *intel_crtc =
>+		to_intel_crtc(intel_dig_port->base.base.crtc);
>+	uint32_t val;
>
>-	mutex_lock(&dev_priv->psr.lock);
>-	if (!dev_priv->psr.enabled) {
>-		mutex_unlock(&dev_priv->psr.lock);
>-		return;
>+	if (dev_priv->psr.active) {
>+		if (wait_for((I915_READ(VLV_PSRSTAT(intel_crtc->pipe)) &
>+			      VLV_EDP_PSR_IN_TRANS) == 0, 250))
>+			WARN(1, "PSR transition took longer than expected\n");

The spec claims this waiting time as 250 micro seconds.
Looks like we are waiting for 250 ms.. No ?

Just curious, did you see this transition during testing ?

Thanks,
Durga

>+
>+		val = I915_READ(VLV_PSRCTL(intel_crtc->pipe));
>+		val &= ~VLV_EDP_PSR_ACTIVE_ENTRY;
>+		val &= ~VLV_EDP_PSR_ENABLE;
>+		val &= ~VLV_EDP_PSR_MODE_MASK;
>+		I915_WRITE(VLV_PSRCTL(intel_crtc->pipe), val);
>+
>+		dev_priv->psr.active = false;
>+	} else {
>+		WARN_ON(vlv_edp_is_psr_enabled_on_pipe(dev, intel_crtc-
>>pipe));
> 	}
>+}
>+
>+static void hsw_edp_psr_disable(struct intel_dp *intel_dp)
>+{
>+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
>+	struct drm_i915_private *dev_priv = dev->dev_private;
>
> 	if (dev_priv->psr.active) {
> 		I915_WRITE(EDP_PSR_CTL(dev),
>@@ -2345,6 +2457,23 @@ void intel_edp_psr_disable(struct intel_dp *intel_dp)
> 	} else {
> 		WARN_ON(I915_READ(EDP_PSR_CTL(dev)) & EDP_PSR_ENABLE);
> 	}
>+}
>+
>+void intel_edp_psr_disable(struct intel_dp *intel_dp)
>+{
>+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
>+	struct drm_i915_private *dev_priv = dev->dev_private;
>+
>+	mutex_lock(&dev_priv->psr.lock);
>+	if (!dev_priv->psr.enabled) {
>+		mutex_unlock(&dev_priv->psr.lock);
>+		return;
>+	}
>+
>+	if (HAS_DDI(dev))
>+		hsw_edp_psr_disable(intel_dp);
>+	else
>+		vlv_edp_psr_disable(intel_dp);
>
> 	dev_priv->psr.enabled = NULL;
> 	mutex_unlock(&dev_priv->psr.lock);
>--
>1.9.3
>
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