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

Hi

So now I finally have the correct spec in hands!

2013/2/25 Rodrigo Vivi rodrigo.vivi@gmail.com:

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;
  

If we set this bit, shouldn't we also set DPCD 0x170 bit 1 to 1?

•           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));
  

I'd reorganize the declarations to avoid calling both intel_dp_to_crtc and intel_dp_to_dev :)

•   u32 ctl_reg = HSW_TVIDEO_DIP_CTL(intel_crtc->cpu_transcoder);
  

Please don't preserve the register contents here. We don't use this register anywhere else for DP yet.

•   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;
  

I don't think this is ever expected, so you could probably WARN() or BUG() here. I see this statement comes from hsw_write_infoframe (intel_hdmi.c), we should probably try to do the WARN/BUG there too.

•   /* As per eDP spec, wait for vblank to send SDP VSC packet */
  

•   intel_wait_for_vblank(dev, intel_crtc->pipe);
  

Please see BSpec page "Pipe Video Data Island Packet". After waiting the vsync you need to disable the DIP first, then write the data.

•   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);
  

According to the PSR enabling guide, "HW also enables VSC DIP when required", so I guess the 3 lines above are not needed.

+}

+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))
  

Is it possible to have intel_edp_is_psr_enable here? If not, maybe WARN it.

•           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
  

This comment is probably missing a few periods.

•    *
  

•    */
  

•   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);
  

I see the lines above match our spec, but I still think Jani's comment from patch "drm/i915: Setup EDP PSR AUX Registers" is applicable here.

•   I915_WRITE(EDP_PSR_AUX_CTL,
  

•              msg_size << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT |
  

•              I915_READ(DPA_AUX_CH_CTL));
  

I don't think this is safe, especially since we're not erasing the original msg size bits from DPA_AUX_CH_CTL. I think we should try to set all the bits of this register without reading DPA_AUX_CH_CTL (maybe extract some code from intel_dp_aux_ch into new functions and call from both here and intel_dp_aux_ch).

Also, I still think you should patch intel_dp_aux_ch to put a WARN in case EDP_PSR_CTL bit 31 is 1.

•   /* 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);
  

This FBC WA won't be needed on real world Hardware.

•   /* WA: Continuous PSR exit Workaround */
  

•   I915_WRITE(EDP_PSR_DEBUG_CTL, EDP_PSR_DEBUG_MASK_MEMUP);
  

•   I915_WRITE(GEN6_PMINTRMSK, 0xffffffff);
  

All they ask is to "disabled unused interrupts", not "disable all interrupts".

+}

+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))
  

Is this possible? Should we WARN here?

•           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))
  

Some big sleeps here. Can't we make them faster?

•           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);
  

So, based on this and on the spec, it means the HW will automagically do the link training for us if it's needed?

+}

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

---

dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel