[Intel-gfx] [PATCH 6/7] drm/i915: Implement PHY lane power gating for CHV
Ville Syrjälä
ville.syrjala at linux.intel.com
Fri May 8 09:05:32 PDT 2015
On Fri, May 08, 2015 at 08:19:12PM +0530, Deepak S wrote:
>
>
> On Friday 10 April 2015 08:51 PM, ville.syrjala at linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >
> > Powergate the PHY lanes when they're not needed. For HDMI all four lanes
> > are needed always, but for DP we can enable only the needed lanes. And
> > when the port is not used all lanes can be power gated. This could
> > reduce power consumption a bit when only a subset of the lanes in the
> > PHY are required.
> >
> > A bit of extra care is needed to reconstruct the initial state of the
> > DPIO_PHY_CONTROL register since we can't read it. So instead we read the
> > actual lane status from the DPLL/PHY_STATUS registers and use that to
> > determine which lanes ought to be powergated initially.
> >
> > Also sprinkle a few debug prints around so that we can monitor the
> > DPIO_PHY_STATUS changes without having to read it and risk corrupting
> > it.
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > ---
> > drivers/gpu/drm/i915/i915_reg.h | 2 +
> > drivers/gpu/drm/i915/intel_dp.c | 8 ++++
> > drivers/gpu/drm/i915/intel_drv.h | 2 +
> > drivers/gpu/drm/i915/intel_hdmi.c | 5 +++
> > drivers/gpu/drm/i915/intel_runtime_pm.c | 69 +++++++++++++++++++++++++++++++--
> > 5 files changed, 82 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 977bad6..34c366a 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -1887,10 +1887,12 @@ enum skl_disp_power_wells {
> > #define DPIO_PHY_STATUS (VLV_DISPLAY_BASE + 0x6240)
> > #define DPLL_PORTD_READY_MASK (0xf)
> > #define DISPLAY_PHY_CONTROL (VLV_DISPLAY_BASE + 0x60100)
> > +#define PHY_CH_POWER_DOWN_OVRD_EN(phy, ch) (1 << (2*(phy)+(ch)+27))
> > #define PHY_LDO_DELAY_0NS 0x0
> > #define PHY_LDO_DELAY_200NS 0x1
> > #define PHY_LDO_DELAY_600NS 0x2
> > #define PHY_LDO_SEQ_DELAY(delay, phy) ((delay) << (2*(phy)+23))
> > +#define PHY_CH_POWER_DOWN_OVRD(mask, phy, ch) ((mask) << (8*(phy)+4*(ch)+11))
> > #define PHY_CH_SU_PSR 0x1
> > #define PHY_CH_DEEP_PSR 0x7
> > #define PHY_CH_POWER_MODE(mode, phy, ch) ((mode) << (6*(phy)+3*(ch)+2))
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index ac38fd8..0b43f99 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -2336,6 +2336,8 @@ static void chv_post_disable_dp(struct intel_encoder *encoder)
> >
> > intel_dp_link_down(intel_dp);
> >
> > + chv_powergate_phy_lanes(encoder, 0xf);
> > +
> > mutex_lock(&dev_priv->dpio_lock);
> >
> > /* Propagate soft reset to data lane reset */
> > @@ -2482,6 +2484,12 @@ static void intel_enable_dp(struct intel_encoder *encoder)
> > if (IS_VALLEYVIEW(dev))
> > vlv_init_panel_power_sequencer(intel_dp);
> >
> > + if (IS_CHERRYVIEW(dev)) {
> > + /* FIXME deal with lane reversal */
> > + lane_mask = 0xf & ~((1 << intel_dp->lane_count) - 1);
> > + chv_powergate_phy_lanes(encoder, lane_mask);
> > + }
> > +
> > intel_dp_enable_port(intel_dp);
> >
> > edp_panel_vdd_on(intel_dp);
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index 3ec829a..54bcca8 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1238,6 +1238,8 @@ void intel_runtime_pm_put(struct drm_i915_private *dev_priv);
> >
> > void intel_display_set_init_power(struct drm_i915_private *dev, bool enable);
> >
> > +void chv_powergate_phy_lanes(struct intel_encoder *encoder, unsigned int mask);
> > +
> > /* intel_pm.c */
> > void intel_init_clock_gating(struct drm_device *dev);
> > void intel_suspend_hw(struct drm_device *dev);
> > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> > index 24b0aa1..f5842c3 100644
> > --- a/drivers/gpu/drm/i915/intel_hdmi.c
> > +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> > @@ -916,6 +916,9 @@ static void intel_disable_hdmi(struct intel_encoder *encoder)
> > I915_WRITE(intel_hdmi->hdmi_reg, temp);
> > POSTING_READ(intel_hdmi->hdmi_reg);
> > }
> > +
> > + if (IS_CHERRYVIEW(dev))
> > + chv_powergate_phy_lanes(encoder, 0xf);
> > }
> >
> > static int hdmi_portclock_limit(struct intel_hdmi *hdmi, bool respect_dvi_limit)
> > @@ -1634,6 +1637,8 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder)
> > intel_crtc->config->has_hdmi_sink,
> > adjusted_mode);
> >
> > + chv_powergate_phy_lanes(encoder, 0x0);
> > +
> > intel_enable_hdmi(encoder);
> >
> > vlv_wait_port_ready(dev_priv, dport, 0x0);
> > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > index 5cd8a51..d9e00d3 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > @@ -668,6 +668,9 @@ static void chv_dpio_cmn_power_well_enable(struct drm_i915_private *dev_priv,
> >
> > dev_priv->chv_phy_control |= PHY_COM_LANE_RESET_DEASSERT(phy);
> > I915_WRITE(DISPLAY_PHY_CONTROL, dev_priv->chv_phy_control);
> > +
> > + DRM_DEBUG_KMS("Enabled DPIO PHY%d (DPIO_PHY_CONTROL=0x%08x)\n",
> > + phy, dev_priv->chv_phy_control);
> > }
> >
> > static void chv_dpio_cmn_power_well_disable(struct drm_i915_private *dev_priv,
> > @@ -680,10 +683,15 @@ static void chv_dpio_cmn_power_well_disable(struct drm_i915_private *dev_priv,
> >
> > if (power_well->data == PUNIT_POWER_WELL_DPIO_CMN_BC) {
> > phy = DPIO_PHY0;
> > + dev_priv->chv_phy_control |=
> > + PHY_CH_POWER_DOWN_OVRD(0xf, phy, DPIO_CH0) |
> > + PHY_CH_POWER_DOWN_OVRD(0xf, phy, DPIO_CH1);
> > assert_pll_disabled(dev_priv, PIPE_A);
> > assert_pll_disabled(dev_priv, PIPE_B);
> > } else {
> > phy = DPIO_PHY1;
> > + dev_priv->chv_phy_control |=
> > + PHY_CH_POWER_DOWN_OVRD(0xf, phy, DPIO_CH0);
> > assert_pll_disabled(dev_priv, PIPE_C);
> > }
> >
> > @@ -691,6 +699,25 @@ static void chv_dpio_cmn_power_well_disable(struct drm_i915_private *dev_priv,
> > I915_WRITE(DISPLAY_PHY_CONTROL, dev_priv->chv_phy_control);
> >
> > vlv_set_power_well(dev_priv, power_well, false);
> > +
> > + DRM_DEBUG_KMS("Disabled DPIO PHY%d (DPIO_PHY_CONTROL=0x%08x)\n",
> > + phy, dev_priv->chv_phy_control);
> > +}
> > +
> > +void chv_powergate_phy_lanes(struct intel_encoder *encoder, unsigned int mask)
> > +{
> > + struct drm_device *dev = encoder->base.dev;
> > + struct drm_i915_private *dev_priv = dev->dev_private;
> > + struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
> > + enum dpio_phy phy = DPIO_PHY(intel_crtc->pipe);
> > + enum dpio_channel ch = vlv_dport_to_channel(enc_to_dig_port(&encoder->base));
> > +
> > + dev_priv->chv_phy_control &= ~PHY_CH_POWER_DOWN_OVRD(0xf, phy, ch);
> > + dev_priv->chv_phy_control |= PHY_CH_POWER_DOWN_OVRD(mask, phy, ch);
> > + I915_WRITE(DISPLAY_PHY_CONTROL, dev_priv->chv_phy_control);
> > +
> > + DRM_DEBUG_KMS("Power gating DPIO PHY%d CH%d lanes 0x%x (DPIO_PHY_CONTROL=0x%08x)\n",
> > + phy, ch, mask, dev_priv->chv_phy_control);
> > }
> >
>
> Hi Ville,
>
> I think based on the spec, we needto program 0x8170 as 0xxxC3xxxx to affect the DDI0 power down
> and this reigster to be programted beforeDPIO_PHY_CONTROL ?
Doh. Nice catch. Looks like the dynamic power down bits default to off.
I also found the same bit in CL2 DW6, which isn't mentioned by the spec.
I'll cook up a patch to flip them and run a few tests to see if stuff
still works.
>
> Thanks
> Deepak
>
> > static bool chv_pipe_power_well_enabled(struct drm_i915_private *dev_priv,
> > @@ -1402,19 +1429,53 @@ static void chv_phy_control_init(struct drm_i915_private *dev_priv)
> > * DISPLAY_PHY_CONTROL can get corrupted if read. As a
> > * workaround never ever read DISPLAY_PHY_CONTROL, and
> > * instead maintain a shadow copy ourselves. Use the actual
> > - * power well state to reconstruct the expected initial
> > - * value.
> > + * power well state and lane status to reconstruct the
> > + * expected initial value.
> > */
> > dev_priv->chv_phy_control =
> > + PHY_CH_POWER_DOWN_OVRD_EN(DPIO_PHY0, DPIO_CH0) |
> > + PHY_CH_POWER_DOWN_OVRD_EN(DPIO_PHY0, DPIO_CH1) |
> > + PHY_CH_POWER_DOWN_OVRD_EN(DPIO_PHY1, DPIO_CH0) |
> > PHY_LDO_SEQ_DELAY(PHY_LDO_DELAY_600NS, DPIO_PHY0) |
> > PHY_LDO_SEQ_DELAY(PHY_LDO_DELAY_600NS, DPIO_PHY1) |
> > PHY_CH_POWER_MODE(PHY_CH_SU_PSR, DPIO_PHY0, DPIO_CH0) |
> > PHY_CH_POWER_MODE(PHY_CH_SU_PSR, DPIO_PHY0, DPIO_CH1) |
> > PHY_CH_POWER_MODE(PHY_CH_SU_PSR, DPIO_PHY1, DPIO_CH0);
> > - if (cmn_bc->ops->is_enabled(dev_priv, cmn_bc))
> > +
> > + if (cmn_bc->ops->is_enabled(dev_priv, cmn_bc)) {
> > + uint32_t status = I915_READ(DPLL(PIPE_A));
> > + unsigned int mask;
> > +
> > + mask = status & DPLL_PORTB_READY_MASK;
> > + dev_priv->chv_phy_control |=
> > + PHY_CH_POWER_DOWN_OVRD(mask, DPIO_PHY0, DPIO_CH0);
> > + mask = (status & DPLL_PORTC_READY_MASK) >> 4;
> > + dev_priv->chv_phy_control |=
> > + PHY_CH_POWER_DOWN_OVRD(mask, DPIO_PHY0, DPIO_CH1);
> > +
> > dev_priv->chv_phy_control |= PHY_COM_LANE_RESET_DEASSERT(DPIO_PHY0);
> > - if (cmn_d->ops->is_enabled(dev_priv, cmn_d))
> > + } else {
> > + dev_priv->chv_phy_control |=
> > + PHY_CH_POWER_DOWN_OVRD(0xf, DPIO_PHY0, DPIO_CH0) |
> > + PHY_CH_POWER_DOWN_OVRD(0xf, DPIO_PHY0, DPIO_CH1);
> > + }
> > +
> > + if (cmn_d->ops->is_enabled(dev_priv, cmn_d)) {
> > + uint32_t status = I915_READ(DPIO_PHY_STATUS);
> > + unsigned int mask;
> > +
> > + mask = status & DPLL_PORTD_READY_MASK;
> > + dev_priv->chv_phy_control |=
> > + PHY_CH_POWER_DOWN_OVRD(mask, DPIO_PHY1, DPIO_CH0);
> > +
> > dev_priv->chv_phy_control |= PHY_COM_LANE_RESET_DEASSERT(DPIO_PHY1);
> > + } else {
> > + dev_priv->chv_phy_control |=
> > + PHY_CH_POWER_DOWN_OVRD(0xf, DPIO_PHY1, DPIO_CH0);
> > + }
> > +
> > + DRM_DEBUG_KMS("Initial DPIO_PHY_CONTROL=0x%08x\n",
> > + dev_priv->chv_phy_control);
> > }
> >
> > static void vlv_cmnlane_wa(struct drm_i915_private *dev_priv)
>
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--
Ville Syrjälä
Intel OTC
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