Re: [PATCH 6/8] drm/i915: Enable/Disable PSR

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Mon, Feb 25, 2013 at 07:55:20PM -0300, Rodrigo Vivi wrote:
> Adding Enable and Disable PSR functionalities. This includes setting the
> PSR configuration over AUX, sending SDP VSC DIP over the eDP PIPE config,
> enabling PSR in the sink via DPCD register and finally enabling PSR on
> the host.
> 
> This patch is heavily based on initial PSR code by Sateesh Kavuri and
> Kumar Shobhit but in a different implementation.
> 
> Credits-by: Sateesh Kavuri <sateesh.kavuri@intel.com>
> Credits-by: Shobhit Kumar <shobhit.kumar@intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h  |  40 +++++++++
>  drivers/gpu/drm/i915/intel_dp.c  | 183 +++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_drv.h |   3 +
>  3 files changed, 226 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index b715ecd..1e31f23 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -844,6 +844,8 @@
>  #define   SNB_CPU_FENCE_ENABLE	(1<<29)
>  #define DPFC_CPU_FENCE_OFFSET	0x100104
>  
> +/* Framebuffer compression for Haswell */
> +#define HSW_FBC_CONTROL		0x43208
>  
>  /*
>   * GPIO regs
> @@ -1580,6 +1582,44 @@
>  #define BCLRPAT(pipe) _PIPE(pipe, _BCLRPAT_A, _BCLRPAT_B)
>  #define VSYNCSHIFT(trans) _TRANSCODER(trans, _VSYNCSHIFT_A, _VSYNCSHIFT_B)
>  
> +/* HSW eDP PSR registers */
> +#define EDP_PSR_CTL				0x64800
> +#define   EDP_PSR_ENABLE			(1<<31)
> +#define   EDP_PSR_LINK_DISABLE			(0<<27)
> +#define   EDP_PSR_LINK_STANDBY			(1<<27)
> +#define   EDP_PSR_MIN_LINK_ENTRY_TIME_MASK	(3<<25)
> +#define   EDP_PSR_MIN_LINK_ENTRY_TIME_8_LINES	(0<<25)
> +#define   EDP_PSR_MIN_LINK_ENTRY_TIME_4_LINES	(1<<25)
> +#define   EDP_PSR_MIN_LINK_ENTRY_TIME_2_LINES	(2<<25)
> +#define   EDP_PSR_MIN_LINK_ENTRY_TIME_0_LINES	(3<<25)
> +#define   EDP_PSR_MAX_SLEEP_TIME_SHIFT		20
> +#define   EDP_PSR_SKIP_AUX_EXIT			(1<<12)
> +#define   EDP_PSR_TP1_TP2_SEL			(0<<11)
> +#define   EDP_PSR_TP1_TP3_SEL			(1<<11)
> +#define   EDP_PSR_TP2_TP3_TIME_500us		(0<<8)
> +#define   EDP_PSR_TP2_TP3_TIME_100us		(1<<8)
> +#define   EDP_PSR_TP2_TP3_TIME_2500us		(2<<8)
> +#define   EDP_PSR_TP2_TP3_TIME_0us		(3<<8)
> +#define   EDP_PSR_TP1_TIME_500us		(0<<4)
> +#define   EDP_PSR_TP1_TIME_100us		(1<<4)
> +#define   EDP_PSR_TP1_TIME_2500us		(2<<4)
> +#define   EDP_PSR_TP1_TIME_0us			(3<<4)
> +#define   EDP_PSR_IDLE_FRAME_SHIFT		0
> +
> +#define EDP_PSR_AUX_CTL			0x64810
> +#define EDP_PSR_AUX_DATA1		0x64814
> +#define EDP_PSR_AUX_DATA2		0x64818
> +#define EDP_PSR_AUX_DATA3		0x6481c
> +#define EDP_PSR_AUX_DATA4		0x64820
> +#define EDP_PSR_AUX_DATA5		0x64824
> +
> +#define EDP_PSR_STATUS_CTL			0x64840
> +#define   EDP_PSR_STATUS_STATE_MASK		(7<<29)
> +
> +#define EDP_PSR_DEBUG_CTL		0x64860
> +#define   EDP_PSR_DEBUG_MASK_MEMUP	(1<<26)
> +#define   EDP_PSR_DEBUG_MASK_HPD	(1<<25)
> +
>  /* VGA port control */
>  #define ADPA			0x61100
>  #define PCH_ADPA                0xe1100
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 5cfa9f4..a420f0d 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -83,6 +83,13 @@ static struct drm_device *intel_dp_to_dev(struct intel_dp *intel_dp)
>  	return intel_dig_port->base.base.dev;
>  }
>  
> +static struct drm_crtc *intel_dp_to_crtc(struct intel_dp *intel_dp)
> +{
> +	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> +
> +	return intel_dig_port->base.base.crtc;
> +}
> +
>  static struct intel_dp *intel_attached_dp(struct drm_connector *connector)
>  {
>  	return enc_to_intel_dp(&intel_attached_encoder(connector)->base);
> @@ -1443,6 +1450,182 @@ static bool is_edp_psr(struct intel_dp *intel_dp)
>  		(intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED));
>  }
>  
> +static bool
> +intel_edp_is_psr_enabled(struct intel_dp* intel_dp)
> +{
> +	struct drm_device *dev = intel_dp_to_dev(intel_dp);
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	return I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE;
> +}
> +
> +static void
> +intel_edp_psr_enable_src(struct intel_dp *intel_dp)
> +{
> +	struct drm_device *dev = intel_dp_to_dev(intel_dp);
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	uint32_t max_sleep_time = 0x1f;
> +	uint32_t val = 0x0;
> +
> +	if (dev_priv->vbt.psr_idle_frames)
> +	    val |= dev_priv->vbt.psr_idle_frames << EDP_PSR_IDLE_FRAME_SHIFT;
> +	else
> +	    val |= 1 << EDP_PSR_IDLE_FRAME_SHIFT;
> +
> +	if (intel_dp->psr_dpcd[1] & DP_PSR_NO_TRAIN_ON_EXIT) {
> +		val |= EDP_PSR_LINK_STANDBY;

There were some WAs for link standby not working on all revisions.
Do we care?

> +		val |= EDP_PSR_TP2_TP3_TIME_0us;
> +		val |= EDP_PSR_TP1_TIME_0us;
> +		val |= EDP_PSR_SKIP_AUX_EXIT;
> +	} else {
> +		val |= EDP_PSR_LINK_DISABLE;
> +		/* Use these Values from VBT
> +		 * Case values are timings for HSW as of now
> +		 * in multiple of 100us
> +		 */
> +		switch(dev_priv->vbt.psr_wakeup_tp1) {
> +			case 1:
> +				val |= EDP_PSR_TP1_TIME_100us;
> +				break;
> +			case 5:
> +				val |= EDP_PSR_TP1_TIME_500us;
> +				break;
> +			case 25:
> +				val |= EDP_PSR_TP1_TIME_2500us;
> +				break;
> +			default:
> +				val |= EDP_PSR_TP1_TIME_500us;
> +				break;
> +		};
> +		switch(dev_priv->vbt.psr_wakeup_tp2_tp3) {
> +			case 1:
> +				val |= EDP_PSR_TP2_TP3_TIME_100us;
> +				break;
> +			case 5:
> +				val |= EDP_PSR_TP2_TP3_TIME_500us;
> +				break;
> +			case 25:
> +				val |= EDP_PSR_TP2_TP3_TIME_2500us;
> +				break;
> +			default:
> +				val |= EDP_PSR_TP2_TP3_TIME_500us;
> +				break;
> +		};
> +	}
> +
> +	I915_WRITE(EDP_PSR_CTL, val |
> +		   EDP_PSR_MIN_LINK_ENTRY_TIME_8_LINES |
> +		   max_sleep_time << EDP_PSR_MAX_SLEEP_TIME_SHIFT |
> +		   EDP_PSR_ENABLE);
> +}
> +
> +void intel_edp_write_vsc_psr(struct intel_dp* intel_dp,
> +			     struct edp_vsc_psr *vsc_psr)
> +{
> +	struct drm_device *dev =  intel_dp_to_dev(intel_dp);
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct intel_crtc *intel_crtc =  to_intel_crtc(intel_dp_to_crtc(intel_dp));
> +	u32 ctl_reg = HSW_TVIDEO_DIP_CTL(intel_crtc->cpu_transcoder);
> +	u32 data_reg = HSW_TVIDEO_DIP_VSC_DATA(intel_crtc->cpu_transcoder);
> +	uint32_t *data = (uint32_t *)vsc_psr;
> +	unsigned int i;
> +	u32 val = I915_READ(ctl_reg);
> +
> +	if (data_reg == 0)
> +		return;
> +
> +	/* As per eDP spec, wait for vblank to send SDP VSC packet */
> +	intel_wait_for_vblank(dev, intel_crtc->pipe);

Is this really needed? Isn't the SDP stuff sent out during vblank by
definition?

> +
> +	mmiowb();
> +	for (i = 0; i < sizeof(struct edp_vsc_psr); i += 4) {
> +		I915_WRITE(data_reg + i, *data);
> +		data++;
> +	}
> +	/* Write every possible data byte to force correct ECC calculation. */
> +	for (; i < VIDEO_DIP_DATA_SIZE; i += 4)
> +		I915_WRITE(data_reg + i, 0);
> +	mmiowb();
> +
> +	val |= VIDEO_DIP_ENABLE_VSC_HSW;
> +	I915_WRITE(ctl_reg, val);
> +	POSTING_READ(ctl_reg);
> +}
> +
> +void intel_edp_enable_psr(struct intel_dp* intel_dp)
> +{
> +	struct drm_device *dev = intel_dp_to_dev(intel_dp);
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct edp_vsc_psr psr_vsc;
> +	int msg_size = 5;       /* Header(4) + Message(1) */
> +
> +	if (!is_edp_psr(intel_dp) || intel_edp_is_psr_enabled(intel_dp))
> +		return;
> +
> +	/* Prepare VSC packet as per EDP 1.3 spec, Table 3.10 */
> +	memset(&psr_vsc, 0, sizeof(psr_vsc));
> +	psr_vsc.sdp_header.id = 0;
> +	psr_vsc.sdp_header.type = 0x7;
> +	psr_vsc.sdp_header.revision = 0x2;
> +	psr_vsc.sdp_header.valid_payload_bytes = 0x8;
> +
> +	intel_edp_write_vsc_psr(intel_dp, &psr_vsc);
> +
> +	/* Enable PSR in sink by setting bit 0 in DPCD config reg
> +	 * along with the transmitter state during PSR active
> +	 * Transmitter state later can be ready from VBT. As of now
> +	 * program the full link down
> +	 *
> +	 */
> +	intel_dp_aux_native_write_1(intel_dp, DP_PSR_EN_CFG,
> +				    DP_PSR_ENABLE);
> +
> +	/* Setup AUX registers */
> +	/* Write command on DPCD 0x0600 */
> +	I915_WRITE(EDP_PSR_AUX_DATA1, 0x80060000);
> +
> +	/* Set the state to normal operation D0 in DPCD 0x0600 */
> +	I915_WRITE(EDP_PSR_AUX_DATA2, 0x01000000);
> +
> +	I915_WRITE(EDP_PSR_AUX_CTL,
> +		   msg_size << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT |
> +		   I915_READ(DPA_AUX_CH_CTL));

Would it be possible to make this stuff a bit more like the normal
aux stuff? Maybe even share some code to set up the data? But then
again it's just these few writes here, so I'm not sure it's worth
the effort.

> +
> +	/* Enable PSR on the host */
> +	intel_edp_psr_enable_src(intel_dp);
> +
> +	/* WA: FBC/PSR Underrun/Corruption Workaround */
> +	I915_WRITE(HSW_FBC_CONTROL, ~FBC_CTL_EN);

Are we expecting that BIOS left FBC enabled? Shouldn't we then disable
it during resume?

> +
> +	/* WA: Continuous PSR exit Workaround */
> +	I915_WRITE(EDP_PSR_DEBUG_CTL, EDP_PSR_DEBUG_MASK_MEMUP);

Shouldn't this be done before enabling PSR?

> +	I915_WRITE(GEN6_PMINTRMSK, 0xffffffff);

I can't find anything about this in bspec or WA db.

> +}
> +
> +void intel_edp_disable_psr(struct intel_dp* intel_dp)
> +{
> +	struct drm_device *dev = intel_dp_to_dev(intel_dp);
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct intel_crtc *intel_crtc = to_intel_crtc(intel_dp_to_crtc(intel_dp));
> +	uint32_t reg = HSW_TVIDEO_DIP_CTL(intel_crtc->cpu_transcoder);
> +	uint32_t val;
> +
> +	if (!intel_edp_is_psr_enabled(intel_dp))
> +		return;
> +
> +	val = I915_READ(EDP_PSR_CTL);
> +	I915_WRITE(EDP_PSR_CTL, val & ~EDP_PSR_ENABLE);
> +
> +	/* Wait till PSR is idle */
> +	if (_wait_for((I915_READ(EDP_PSR_STATUS_CTL) &
> +		       EDP_PSR_STATUS_STATE_MASK) == 0, 2000, 10))
> +		DRM_ERROR("Timed out waiting for PSR Idle State\n");
> +
> +	intel_wait_for_vblank(dev, intel_crtc->pipe);
> +
> +	val = I915_READ(reg);
> +	I915_WRITE(reg, val & ~VIDEO_DIP_ENABLE_VSC_HSW);
> +}
> +
>  static void intel_enable_dp(struct intel_encoder *encoder)
>  {
>  	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 865ede6..cfda739 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -696,4 +696,7 @@ extern bool
>  intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector);
>  extern void intel_ddi_fdi_disable(struct drm_crtc *crtc);
>  
> +extern void intel_edp_enable_psr(struct intel_dp* intel_dp);
> +extern void intel_edp_disable_psr(struct intel_dp* intel_dp);
> +
>  #endif /* __INTEL_DRV_H__ */
> -- 
> 1.8.1.2
> 
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-- 
Ville Syrjälä
Intel OTC