[Intel-gfx] [PATCH] drm/i915: Enable FBC at Haswell.

Rodrigo Vivi rodrigo.vivi at gmail.com
Tue Apr 16 22:54:44 CEST 2013


On Tue, Apr 16, 2013 at 2:49 PM, Ville Syrjälä <
ville.syrjala at linux.intel.com> wrote:

> On Tue, Apr 16, 2013 at 01:33:44PM -0300, Rodrigo Vivi wrote:
> > This patch introduce Frame Buffer Compression (FBC) support for HSW.
> > It adds a new function haswell_enable_fbc to avoid getting
> > ironlake_enable_fbc messed with many IS_HASWELL checks.
> >
> > v2: Fixes from Ville.
> >       *  Fix Plane. FBC is tied to primary plane A in HSW
> >       *  Fix DPFC initial write to avoid let trash on the register.
> >
> > v3: Checking for bad plane on intel_update_fbc() as Chris suggested.
> >
> > v4: Ville pointed out that according to BSpec FBC_CTL bits 0:3 must be 0.
> >
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>
> > ---
> >  drivers/gpu/drm/i915/i915_drv.c |  1 +
> >  drivers/gpu/drm/i915/i915_reg.h |  6 ++++++
> >  drivers/gpu/drm/i915/intel_pm.c | 42
> +++++++++++++++++++++++++++++++++++++++--
> >  3 files changed, 47 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_drv.c
> b/drivers/gpu/drm/i915/i915_drv.c
> > index 9ebe895..ba0935d 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.c
> > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > @@ -314,6 +314,7 @@ static const struct intel_device_info
> intel_haswell_m_info = {
> >       GEN7_FEATURES,
> >       .is_haswell = 1,
> >       .is_mobile = 1,
> > +     .has_fbc = 1,
> >  };
> >
> >  static const struct pci_device_id pciidlist[] = {            /* aka */
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h
> > index 077d40f..b9725ba 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -857,6 +857,12 @@
> >  #define   SNB_CPU_FENCE_ENABLE       (1<<29)
> >  #define DPFC_CPU_FENCE_OFFSET        0x100104
> >
> > +/* Framebuffer compression for Haswell */
> > +#define HSW_FBC_RT_BASE                      0x7020
> > +#define   HSW_FBC_RT_BASE_ADDR_SHIFT 12
> > +
> > +#define   HSW_DPFC_CTL_FENCE_EN              (1<<28)
> > +#define   HSW_DPFC_CTL_DISABLE_SLB_INIT      (1<<15)
>
> These registers/bits already exists on IVB. All the registers you set
> seem to be in line with IVB BSpec, so I think you just need to to
> s/haswell/gen7/ everywhere, and then we get FBC for IVB for free.
>
> Well, the only real work left would be adding plane B and C FBC
> support on IVB.
>

I implemented here the ivb version, tested and it didn't worked.
So I believe we can go on with HSW names and change it in the future if we
can really get fbc working on ivb.
What do you think?


>
> The new DPFC_CTL bits should also probably be grouped with the rest of
> the ILK_DPFC_CONTROL bits, otherwise it's difficult to know which
> register they belong to.
>

I just didn't do this because it was already organized by platforms. But it
makes sense. coming on v5.


>
> >
> >  /*
> >   * GPIO regs
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c
> b/drivers/gpu/drm/i915/intel_pm.c
> > index f747cb0..7b20fc5 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -253,6 +253,38 @@ static bool ironlake_fbc_enabled(struct drm_device
> *dev)
> >       return I915_READ(ILK_DPFC_CONTROL) & DPFC_CTL_EN;
> >  }
> >
> > +static void haswell_enable_fbc(struct drm_crtc *crtc, unsigned long
> interval)
> > +{
> > +     struct drm_device *dev = crtc->dev;
> > +     struct drm_i915_private *dev_priv = dev->dev_private;
> > +     struct drm_framebuffer *fb = crtc->fb;
> > +     struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
> > +     struct drm_i915_gem_object *obj = intel_fb->obj;
> > +     struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> > +     unsigned long stall_watermark = 200;
> > +
> > +     I915_WRITE(ILK_DPFC_RECOMP_CTL, DPFC_RECOMP_STALL_EN |
> > +                (stall_watermark << DPFC_RECOMP_STALL_WM_SHIFT) |
> > +                (interval << DPFC_RECOMP_TIMER_COUNT_SHIFT));
> > +     I915_WRITE(HSW_FBC_RT_BASE,
> > +                obj->gtt_offset << HSW_FBC_RT_BASE_ADDR_SHIFT |
> > +                ILK_FBC_RT_VALID);
> > +
> > +     I915_WRITE(ILK_DPFC_CONTROL, DPFC_CTL_EN | DPFC_CTL_LIMIT_1X |
> > +                HSW_DPFC_CTL_FENCE_EN | HSW_DPFC_CTL_DISABLE_SLB_INIT);
> > +
> > +     if (obj->fence_reg != I915_FENCE_REG_NONE) {
>
> Is there actually a case that we wouldn't have a fence? I think we
> always reserve a fence for scanout even though we wouldn't really
> need it on gen4+ (or for untiled on gen2-3). At least we don't have any
> sanity checks for fence_reg in the ironlake_enable_fbc().
>

Yeah, you are right. I don't see any case without the fence. So I'm going
to remove this check and else block in v5.


>
> But if this can happen, then shouldn't we also clear the
> "fence enable" bit from ILK_DPFC_CONTROL?


> > +             I915_WRITE(SNB_DPFC_CTL_SA,
> > +                        SNB_CPU_FENCE_ENABLE | obj->fence_reg);
> > +             I915_WRITE(DPFC_CPU_FENCE_OFFSET, crtc->y);
> > +     } else
> > +             I915_WRITE(SNB_DPFC_CTL_SA, ~SNB_CPU_FENCE_ENABLE);
> > +
> > +     sandybridge_blit_fbc_update(dev);
> > +
> > +     DRM_DEBUG_KMS("enabled fbc on plane A\n");
> > +}
> > +
> >  bool intel_fbc_enabled(struct drm_device *dev)
> >  {
> >       struct drm_i915_private *dev_priv = dev->dev_private;
> > @@ -460,7 +492,8 @@ void intel_update_fbc(struct drm_device *dev)
> >               dev_priv->no_fbc_reason = FBC_MODE_TOO_LARGE;
> >               goto out_disable;
> >       }
> > -     if ((IS_I915GM(dev) || IS_I945GM(dev)) && intel_crtc->plane != 0) {
> > +     if ((IS_I915GM(dev) || IS_I945GM(dev) || IS_HASWELL(dev))
> > +         && intel_crtc->plane != 0) {
> >               DRM_DEBUG_KMS("plane not 0, disabling compression\n");
> >               dev_priv->no_fbc_reason = FBC_BAD_PLANE;
> >               goto out_disable;
> > @@ -4180,7 +4213,12 @@ void intel_init_pm(struct drm_device *dev)
> >       if (I915_HAS_FBC(dev)) {
> >               if (HAS_PCH_SPLIT(dev)) {
> >                       dev_priv->display.fbc_enabled =
> ironlake_fbc_enabled;
> > -                     dev_priv->display.enable_fbc = ironlake_enable_fbc;
> > +                     if (IS_HASWELL(dev))
> > +                             dev_priv->display.enable_fbc =
> > +                                     haswell_enable_fbc;
> > +                     else
> > +                             dev_priv->display.enable_fbc =
> > +                                     ironlake_enable_fbc;
> >                       dev_priv->display.disable_fbc =
> ironlake_disable_fbc;
> >               } else if (IS_GM45(dev)) {
> >                       dev_priv->display.fbc_enabled = g4x_fbc_enabled;
> > --
> > 1.8.1.4
>
> --
> Ville Syrjälä
> Intel OTC
>



-- 
Rodrigo Vivi
Blog: http://blog.vivi.eng.br
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