[Intel-gfx] [PATCH 1/3] drm/i915: implement IPS feature

Rodrigo Vivi rodrigo.vivi at gmail.com
Sat May 18 05:18:07 CEST 2013


Reviewed-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>

On Thu, May 16, 2013 at 4:54 PM, Paulo Zanoni <przanoni at gmail.com> wrote:
> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>
> Intermediate Pixel Storage is a feature that should reduce the number
> of times the display engine wakes up memory to read pixels, so it
> should allow deeper PC states. IPS can only be enabled on ULT pipe A
> with 8:8:8 pipe pixel formats.
>
> With eDP 1920x1080 and correct watermarks but without FBC this moves
> my PC7 residency from 2.5% to around 38%.
>
> v2: - It's tied to pipe A, not port A
>     - Add pipe_config support (Chris)
>     - Add some assertions (Chris)
>     - Rebase against latest dinq
>
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h      | 11 +++++
>  drivers/gpu/drm/i915/intel_display.c | 79 +++++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/i915/intel_drv.h     |  2 +
>  3 files changed, 90 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 32eb97c..65339a7 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -977,6 +977,8 @@
>  /* Framebuffer compression for Ivybridge */
>  #define IVB_FBC_RT_BASE                        0x7020
>
> +#define IPS_CTL                0x43408
> +#define   IPS_ENABLE   (1 << 31)
>
>  #define _HSW_PIPE_SLICE_CHICKEN_1_A    0x420B0
>  #define _HSW_PIPE_SLICE_CHICKEN_1_B    0x420B4
> @@ -3621,6 +3623,15 @@
>  #define _LGC_PALETTE_B           0x4a800
>  #define LGC_PALETTE(pipe) _PIPE(pipe, _LGC_PALETTE_A, _LGC_PALETTE_B)
>
> +#define _GAMMA_MODE_A          0x4a480
> +#define _GAMMA_MODE_B          0x4ac80
> +#define GAMMA_MODE(pipe) _PIPE(pipe, _GAMMA_MODE_A, _GAMMA_MODE_B)
> +#define GAMMA_MODE_MODE_MASK   (3 << 0)
> +#define GAMMA_MODE_MODE_8bit   (0 << 0)
> +#define GAMMA_MODE_MODE_10bit  (1 << 0)
> +#define GAMMA_MODE_MODE_12bit  (2 << 0)
> +#define GAMMA_MODE_MODE_SPLIT  (3 << 0)
> +
>  /* interrupts */
>  #define DE_MASTER_IRQ_CONTROL   (1 << 31)
>  #define DE_SPRITEB_FLIP_DONE    (1 << 29)
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index d588ff6..5b41cf3 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -3340,6 +3340,53 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
>         intel_wait_for_vblank(dev, intel_crtc->pipe);
>  }
>
> +/* IPS only exists on ULT machines and is tied to pipe A. */
> +static bool hsw_crtc_supports_ips(struct intel_crtc *crtc)
> +{
> +       return (IS_ULT(crtc->base.dev) && crtc->pipe == PIPE_A);
> +}
> +
> +static void hsw_enable_ips(struct intel_crtc *crtc)
> +{
> +       struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
> +
> +       if (!hsw_crtc_supports_ips(crtc))
> +               return;
> +
> +       if (crtc->config.pipe_bpp != 24)
> +               return;
> +
> +       DRM_DEBUG_KMS("Enabling IPS\n");
> +
> +       crtc->config.ips_enabled = true;
> +
> +       /* We can only enable IPS after we enable a plane and wait for a vblank.
> +        * We guarantee that the plane is enabled by calling intel_enable_ips
> +        * only after intel_enable_plane. And intel_enable_plane already waits
> +        * for a vblank, so all we need to do here is to enable the IPS bit. */
> +       assert_plane_enabled(dev_priv, crtc->plane);
> +       I915_WRITE(IPS_CTL, IPS_ENABLE);
> +}
> +
> +static void hsw_disable_ips(struct intel_crtc *crtc)
> +{
> +       struct drm_device *dev = crtc->base.dev;
> +       struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +       if (!hsw_crtc_supports_ips(crtc))
> +               return;
> +
> +       DRM_DEBUG_KMS("Disabling IPS\n");
> +
> +       crtc->config.ips_enabled = false;
> +
> +       assert_plane_enabled(dev_priv, crtc->plane);
> +       I915_WRITE(IPS_CTL, 0);
> +
> +       /* We need to wait for a vblank before we can disable the plane. */
> +       intel_wait_for_vblank(dev, crtc->pipe);
> +}
> +
>  static void haswell_crtc_enable(struct drm_crtc *crtc)
>  {
>         struct drm_device *dev = crtc->dev;
> @@ -3387,6 +3434,8 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
>                           intel_crtc->config.has_pch_encoder);
>         intel_enable_plane(dev_priv, plane, pipe);
>
> +       hsw_enable_ips(intel_crtc);
> +
>         if (intel_crtc->config.has_pch_encoder)
>                 lpt_pch_enable(crtc);
>
> @@ -3529,6 +3578,8 @@ static void haswell_crtc_disable(struct drm_crtc *crtc)
>         if (dev_priv->cfb_plane == plane)
>                 intel_disable_fbc(dev);
>
> +       hsw_disable_ips(intel_crtc);
> +
>         intel_disable_plane(dev_priv, plane, pipe);
>
>         if (intel_crtc->config.has_pch_encoder)
> @@ -5021,6 +5072,8 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
>
>         i9xx_get_pfit_config(crtc, pipe_config);
>
> +       pipe_config->ips_enabled = false;
> +
>         return true;
>  }
>
> @@ -5890,6 +5943,8 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
>
>         ironlake_get_pfit_config(crtc, pipe_config);
>
> +       pipe_config->ips_enabled = false;
> +
>         return true;
>  }
>
> @@ -6041,6 +6096,9 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
>         if (intel_display_power_enabled(dev, pfit_domain))
>                 ironlake_get_pfit_config(crtc, pipe_config);
>
> +       pipe_config->ips_enabled = hsw_crtc_supports_ips(crtc) &&
> +                                  (I915_READ(IPS_CTL) & IPS_ENABLE);
> +
>         return true;
>  }
>
> @@ -6345,8 +6403,10 @@ void intel_crtc_load_lut(struct drm_crtc *crtc)
>         struct drm_device *dev = crtc->dev;
>         struct drm_i915_private *dev_priv = dev->dev_private;
>         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> -       int palreg = PALETTE(intel_crtc->pipe);
> +       enum pipe pipe = intel_crtc->pipe;
> +       int palreg = PALETTE(pipe);
>         int i;
> +       bool reenable_ips = false;
>
>         /* The clocks have to be on to load the palette. */
>         if (!crtc->enabled || !intel_crtc->active)
> @@ -6354,7 +6414,17 @@ void intel_crtc_load_lut(struct drm_crtc *crtc)
>
>         /* use legacy palette for Ironlake */
>         if (HAS_PCH_SPLIT(dev))
> -               palreg = LGC_PALETTE(intel_crtc->pipe);
> +               palreg = LGC_PALETTE(pipe);
> +
> +       /* Workaround : Do not read or write the pipe palette/gamma data while
> +        * GAMMA_MODE is configured for split gamma and IPS_CTL has IPS enabled.
> +        */
> +       if (intel_crtc->config.ips_enabled &&
> +           ((I915_READ(GAMMA_MODE(pipe)) & GAMMA_MODE_MODE_MASK) ==
> +            GAMMA_MODE_MODE_SPLIT)) {
> +               hsw_disable_ips(intel_crtc);
> +               reenable_ips = true;
> +       }
>
>         for (i = 0; i < 256; i++) {
>                 I915_WRITE(palreg + 4 * i,
> @@ -6362,6 +6432,9 @@ void intel_crtc_load_lut(struct drm_crtc *crtc)
>                            (intel_crtc->lut_g[i] << 8) |
>                            intel_crtc->lut_b[i]);
>         }
> +
> +       if (reenable_ips)
> +               hsw_enable_ips(intel_crtc);
>  }
>
>  static void i845_update_cursor(struct drm_crtc *crtc, u32 base)
> @@ -8064,6 +8137,8 @@ intel_pipe_config_compare(struct drm_device *dev,
>         PIPE_CONF_CHECK_I(pch_pfit.pos);
>         PIPE_CONF_CHECK_I(pch_pfit.size);
>
> +       PIPE_CONF_CHECK_I(ips_enabled);
> +
>  #undef PIPE_CONF_CHECK_I
>  #undef PIPE_CONF_CHECK_FLAGS
>
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index ba05cc7..5e4844a 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -264,6 +264,8 @@ struct intel_crtc_config {
>         /* FDI configuration, only valid if has_pch_encoder is set. */
>         int fdi_lanes;
>         struct intel_link_m_n fdi_m_n;
> +
> +       bool ips_enabled;
>  };
>
>  struct intel_crtc {
> --
> 1.8.1.2
>
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-- 
Rodrigo Vivi
Blog: http://blog.vivi.eng.br



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