> -----Original Message-----
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Sent: Friday, April 19, 2024 9:38 PM
> To: Murthy, Arun R <arun.r.murthy@xxxxxxxxx>
> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH 1/6] drm/i915: Align PLANE_SURF to 16k on ADL for async
> flips
>
> On Fri, Apr 19, 2024 at 04:20:40AM +0000, Murthy, Arun R wrote:
> >
> > > -----Original Message-----
> > > From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf
> > > Of Ville Syrjala
> > > Sent: Wednesday, March 20, 2024 9:34 PM
> > > To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> > > Subject: [PATCH 1/6] drm/i915: Align PLANE_SURF to 16k on ADL for
> > > async flips
> > >
> > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > >
> > > On ADL async flips apparently generate DMAR and GGTT faults (with
> > > accompanying visual glitches) unless PLANE_SURF is aligned to at least 16k.
> > > Bump up the alignment to 16k.
> >
> > I don’t find any such restriction in the spec. Can you please add link to the
> spec?
>
> I don't think it's documented, hence the FIXME.
>
Ok!
Reviewed-by: Arun R Murthy <arun.r.murthy@xxxxxxxxx>
Thanks and Regards,
Arun R Murthy
--------------------
> >
> > Thanks and Regards,
> > Arun R Murthy
> > -------------------
> > >
> > > TODO: analyze things better to figure out what is really
> > > going on here
> > >
> > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/i915/display/intel_dpt.c | 7 ++++---
> > > drivers/gpu/drm/i915/display/intel_dpt.h | 3 ++-
> > > drivers/gpu/drm/i915/display/intel_fb.c | 17 ++++++++++++++++-
> > > drivers/gpu/drm/i915/display/intel_fb_pin.c | 10 +++++-----
> > > 4 files changed, 27 insertions(+), 10 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dpt.c
> > > b/drivers/gpu/drm/i915/display/intel_dpt.c
> > > index b29bceff73f2..786d3f2e94c7 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dpt.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dpt.c
> > > @@ -121,7 +121,8 @@ static void dpt_cleanup(struct
> > > i915_address_space
> > > *vm)
> > > i915_gem_object_put(dpt->obj);
> > > }
> > >
> > > -struct i915_vma *intel_dpt_pin(struct i915_address_space *vm)
> > > +struct i915_vma *intel_dpt_pin(struct i915_address_space *vm,
> > > + unsigned int alignment)
> > > {
> > > struct drm_i915_private *i915 = vm->i915;
> > > struct i915_dpt *dpt = i915_vm_to_dpt(vm); @@ -143,8 +144,8 @@
> > > struct i915_vma *intel_dpt_pin(struct i915_address_space *vm)
> > > if (err)
> > > continue;
> > >
> > > - vma = i915_gem_object_ggtt_pin_ww(dpt->obj, &ww, NULL, 0,
> > > 4096,
> > > - pin_flags);
> > > + vma = i915_gem_object_ggtt_pin_ww(dpt->obj, &ww, NULL, 0,
> > > + alignment, pin_flags);
> > > if (IS_ERR(vma)) {
> > > err = PTR_ERR(vma);
> > > continue;
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dpt.h
> > > b/drivers/gpu/drm/i915/display/intel_dpt.h
> > > index e18a9f767b11..f467578a4950 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dpt.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_dpt.h
> > > @@ -13,7 +13,8 @@ struct i915_vma;
> > > struct intel_framebuffer;
> > >
> > > void intel_dpt_destroy(struct i915_address_space *vm); -struct
> > > i915_vma *intel_dpt_pin(struct i915_address_space *vm);
> > > +struct i915_vma *intel_dpt_pin(struct i915_address_space *vm,
> > > + unsigned int alignment);
> > > void intel_dpt_unpin(struct i915_address_space *vm); void
> > > intel_dpt_suspend(struct drm_i915_private *i915); void
> > > intel_dpt_resume(struct drm_i915_private *i915); diff --git
> > > a/drivers/gpu/drm/i915/display/intel_fb.c
> > > b/drivers/gpu/drm/i915/display/intel_fb.c
> > > index 3ea6470d6d92..58ead05fba6f 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_fb.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_fb.c
> > > @@ -805,8 +805,23 @@ unsigned int intel_surf_alignment(const struct
> > > drm_framebuffer *fb, {
> > > struct drm_i915_private *dev_priv = to_i915(fb->dev);
> > >
> > > - if (intel_fb_uses_dpt(fb))
> > > + if (intel_fb_uses_dpt(fb)) {
> > > + /* AUX_DIST needs only 4K alignment */
> > > + if (intel_fb_is_ccs_aux_plane(fb, color_plane))
> > > + return 512 * 4096;
> > > +
> > > + /*
> > > + * FIXME ADL sees GGTT/DMAR faults with async
> > > + * flips unless we align to 16k at least.
> > > + * Figure out what's going on here...
> > > + */
> > > + if (IS_ALDERLAKE_P(dev_priv) &&
> > > + !intel_fb_is_ccs_modifier(fb->modifier) &&
> > > + HAS_ASYNC_FLIPS(dev_priv))
> > > + return 512 * 16 * 1024;
> > > +
> > > return 512 * 4096;
> > > + }
> > >
> > > /* AUX_DIST needs only 4K alignment */
> > > if (intel_fb_is_ccs_aux_plane(fb, color_plane)) diff --git
> > > a/drivers/gpu/drm/i915/display/intel_fb_pin.c
> > > b/drivers/gpu/drm/i915/display/intel_fb_pin.c
> > > index 7b42aef37d2f..c28ae99ebe6a 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_fb_pin.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_fb_pin.c
> > > @@ -19,6 +19,7 @@
> > > static struct i915_vma *
> > > intel_pin_fb_obj_dpt(struct drm_framebuffer *fb,
> > > const struct i915_gtt_view *view,
> > > + unsigned int alignment,
> > > bool uses_fence,
> > > unsigned long *out_flags,
> > > struct i915_address_space *vm) @@ -28,7 +29,6 @@
> > > intel_pin_fb_obj_dpt(struct drm_framebuffer *fb,
> > > struct drm_i915_gem_object *obj = intel_fb_obj(fb);
> > > struct i915_gem_ww_ctx ww;
> > > struct i915_vma *vma;
> > > - u32 alignment;
> > > int ret;
> > >
> > > /*
> > > @@ -41,8 +41,6 @@ intel_pin_fb_obj_dpt(struct drm_framebuffer *fb,
> > > if (WARN_ON(!i915_gem_object_is_framebuffer(obj)))
> > > return ERR_PTR(-EINVAL);
> > >
> > > - alignment = 4096 * 512;
> > > -
> > > atomic_inc(&dev_priv->gpu_error.pending_fb_pin);
> > >
> > > for_i915_gem_ww(&ww, ret, true) {
> > > @@ -257,14 +255,16 @@ int intel_plane_pin_fb(struct
> > > intel_plane_state
> > > *plane_state)
> > > plane_state->ggtt_vma = vma;
> > > } else {
> > > struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
> > > + unsigned int alignment = intel_surf_alignment(fb, 0);
> > >
> > > - vma = intel_dpt_pin(intel_fb->dpt_vm);
> > > + vma = intel_dpt_pin(intel_fb->dpt_vm, alignment / 512);
> > > if (IS_ERR(vma))
> > > return PTR_ERR(vma);
> > >
> > > plane_state->ggtt_vma = vma;
> > >
> > > - vma = intel_pin_fb_obj_dpt(fb, &plane_state->view.gtt, false,
> > > + vma = intel_pin_fb_obj_dpt(fb, &plane_state->view.gtt,
> > > + alignment, false,
> > > &plane_state->flags, intel_fb-
> > > >dpt_vm);
> > > if (IS_ERR(vma)) {
> > > intel_dpt_unpin(intel_fb->dpt_vm);
> > > --
> > > 2.43.2
> >
>
> --
> Ville Syrjälä
> Intel
