From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH 02/25] drm/i915: Add vblank notify mechanism Date: Wed, 18 Jun 2014 21:53:48 +0200 Message-ID: <20140618195348.GR5821@phenom.ffwll.local> References: <1403114338-30513-1-git-send-email-ville.syrjala@linux.intel.com> <1403114338-30513-3-git-send-email-ville.syrjala@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail-wg0-f51.google.com (mail-wg0-f51.google.com [74.125.82.51]) by gabe.freedesktop.org (Postfix) with ESMTP id BDE736E779 for ; Wed, 18 Jun 2014 12:53:55 -0700 (PDT) Received: by mail-wg0-f51.google.com with SMTP id x12so1347601wgg.22 for ; Wed, 18 Jun 2014 12:53:55 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1403114338-30513-3-git-send-email-ville.syrjala@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: ville.syrjala@linux.intel.com Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Wed, Jun 18, 2014 at 08:58:35PM +0300, ville.syrjala@linux.intel.com wro= te: > From: Ville Syrj=E4l=E4 > = > Add a vblank notify mechanism where you can ask for a callback when a > specific frame counter value has been passed. > = > This could be used for various things like FBC, IPS, watermarks, > and updating single buffered display registers from the interrupt > handler (eg. gamma). > = > As gen2 doesn't have a hardware frame counter we use the software vblank > counter drm core procvides. This is rather racy, but for something like > FBC it doesn't matter too much. For gen2 we could just scheudle the FBC > enable happen a frame later than on other gens. That should paper over > the races sufficiently. > = > Signed-off-by: Ville Syrj=E4l=E4 Chris submitted a very similar patch for vblank work items, same review still applies: This should be moved into drm_irq.c -Daniel > --- > drivers/gpu/drm/i915/i915_irq.c | 8 +++ > drivers/gpu/drm/i915/intel_display.c | 132 +++++++++++++++++++++++++++++= ++++++ > drivers/gpu/drm/i915/intel_drv.h | 16 +++++ > 3 files changed, 156 insertions(+) > = > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_= irq.c > index 218f011..a908a55 100644 > --- a/drivers/gpu/drm/i915/i915_irq.c > +++ b/drivers/gpu/drm/i915/i915_irq.c > @@ -1736,7 +1736,15 @@ static bool intel_pipe_handle_vblank(struct drm_de= vice *dev, enum pipe pipe) > if (!drm_handle_vblank(dev, pipe)) > return false; > = > + if (!drm_core_check_feature(dev, DRIVER_MODESET)) > + return true; > + > crtc =3D to_intel_crtc(intel_get_crtc_for_pipe(dev, pipe)); > + > + spin_lock(&crtc->lock); > + intel_vblank_notify_check(crtc); > + spin_unlock(&crtc->lock); > + > wake_up(&crtc->vbl_wait); > = > return true; > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/= intel_display.c > index 5e8e711..be3ee69 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -11499,6 +11499,9 @@ static void intel_crtc_init(struct drm_device *de= v, int pipe) > = > init_waitqueue_head(&intel_crtc->vbl_wait); > = > + spin_lock_init(&intel_crtc->lock); > + INIT_LIST_HEAD(&intel_crtc->vblank_notify_list); > + > BUG_ON(pipe >=3D ARRAY_SIZE(dev_priv->plane_to_crtc_mapping) || > dev_priv->plane_to_crtc_mapping[intel_crtc->plane] !=3D NULL); > dev_priv->plane_to_crtc_mapping[intel_crtc->plane] =3D &intel_crtc->bas= e; > @@ -13051,3 +13054,132 @@ intel_display_print_error_state(struct drm_i915= _error_state_buf *m, > err_printf(m, " VSYNC: %08x\n", error->transcoder[i].vsync); > } > } > + > +/* is a after b? */ > +static bool vbl_count_after_eq(struct drm_device *dev, u32 a, u32 b) > +{ > + u32 mask =3D dev->max_vblank_count; > + > + /* now hardware counter on gen2 */ > + if (mask =3D=3D 0) > + mask =3D -1; > + > + mask &=3D (mask >> 1); > + > + return !((a - b) & mask); > +} > + > +static void intel_vblank_notify_complete(struct intel_vblank_notify *not= ify) > +{ > + struct intel_crtc *crtc =3D notify->crtc; > + struct drm_device *dev =3D crtc->base.dev; > + > + assert_spin_locked(&crtc->lock); > + > + drm_vblank_put(dev, crtc->pipe); > + list_del(¬ify->list); > + notify->crtc =3D NULL; > +} > + > +void intel_vblank_notify_check(struct intel_crtc *crtc) > +{ > + struct drm_device *dev =3D crtc->base.dev; > + struct drm_vblank_crtc *vblank =3D > + &dev->vblank[drm_crtc_index(&crtc->base)]; > + struct intel_vblank_notify *notify, *next; > + u32 vbl_count; > + > + assert_spin_locked(&crtc->lock); > + > + if (list_empty(&crtc->vblank_notify_list)) > + return; > + > + /* no hardware frame counter on gen2 */ > + if (dev->max_vblank_count =3D=3D 0) > + vbl_count =3D atomic_read(&vblank->count); > + else > + vbl_count =3D dev->driver->get_vblank_counter(dev, crtc->pipe); > + > + list_for_each_entry_safe(notify, next, &crtc->vblank_notify_list, list)= { > + if (!vbl_count_after_eq(dev, vbl_count, notify->vbl_count)) > + continue; > + > + intel_vblank_notify_complete(notify); > + notify->notify(notify); > + } > +} > + > +int intel_vblank_notify_add(struct intel_crtc *crtc, > + struct intel_vblank_notify *notify) > +{ > + struct drm_device *dev =3D crtc->base.dev; > + unsigned long irqflags; > + u32 vbl_count; > + int ret; > + > + if (WARN_ON(notify->crtc)) > + return -EINVAL; > + > + ret =3D drm_vblank_get(dev, crtc->pipe); > + if (ret) > + return ret; > + > + spin_lock_irqsave(&crtc->lock, irqflags); > + > + notify->crtc =3D crtc; > + list_add(¬ify->list, &crtc->vblank_notify_list); > + > + /* no hardware frame counter on gen2 */ > + if (dev->max_vblank_count =3D=3D 0) { > + struct drm_vblank_crtc *vblank =3D > + &dev->vblank[drm_crtc_index(&crtc->base)]; > + > + vbl_count =3D atomic_read(&vblank->count); > + } else { > + vbl_count =3D dev->driver->get_vblank_counter(dev, crtc->pipe); > + } > + > + if (vbl_count_after_eq(dev, vbl_count, notify->vbl_count)) { > + intel_vblank_notify_complete(notify); > + notify->notify(notify); > + } > + > + spin_unlock_irqrestore(&crtc->lock, irqflags); > + > + return 0; > +} > + > +bool intel_vblank_notify_pending(struct intel_vblank_notify *notify) > +{ > + return notify->crtc !=3D NULL; > +} > + > +void intel_vblank_notify_cancel(struct intel_vblank_notify *notify) > +{ > + struct intel_crtc *crtc =3D ACCESS_ONCE(notify->crtc); > + unsigned long irqflags; > + > + if (!crtc) > + return; > + > + spin_lock_irqsave(&crtc->lock, irqflags); > + if (notify->crtc) > + intel_vblank_notify_complete(notify); > + spin_unlock_irqrestore(&crtc->lock, irqflags); > +} > + > +u32 intel_crtc_vbl_count_rel_to_abs(struct intel_crtc *crtc, u32 rel) > +{ > + struct drm_device *dev =3D crtc->base.dev; > + > + /* now hardware counter on gen2 */ > + if (dev->max_vblank_count =3D=3D 0) { > + struct drm_vblank_crtc *vblank =3D > + &dev->vblank[drm_crtc_index(&crtc->base)]; > + > + return atomic_read(&vblank->count) + rel; > + } > + > + return (dev->driver->get_vblank_counter(dev, crtc->pipe) + rel) & > + dev->max_vblank_count; > +} > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/inte= l_drv.h > index ab5962b..c93626b 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -358,6 +358,13 @@ struct intel_pipe_wm { > bool sprites_scaled; > }; > = > +struct intel_vblank_notify { > + void (*notify)(struct intel_vblank_notify *notify); > + struct intel_crtc *crtc; > + struct list_head list; > + u32 vbl_count; > +}; > + > struct intel_mmio_flip { > u32 seqno; > u32 ring_id; > @@ -417,6 +424,9 @@ struct intel_crtc { > = > int scanline_offset; > struct intel_mmio_flip mmio_flip; > + > + struct list_head vblank_notify_list; > + spinlock_t lock; > }; > = > struct intel_plane_wm_parameters { > @@ -811,6 +821,12 @@ void intel_mode_from_pipe_config(struct drm_display_= mode *mode, > struct intel_crtc_config *pipe_config); > int intel_format_to_fourcc(int format); > void intel_crtc_wait_for_pending_flips(struct drm_crtc *crtc); > +int intel_vblank_notify_add(struct intel_crtc *crtc, > + struct intel_vblank_notify *notify); > +void intel_vblank_notify_cancel(struct intel_vblank_notify *notify); > +bool intel_vblank_notify_pending(struct intel_vblank_notify *notify); > +void intel_vblank_notify_check(struct intel_crtc *crtc); > +u32 intel_crtc_vbl_count_rel_to_abs(struct intel_crtc *crtc, u32 rel); > = > = > /* intel_dp.c */ > -- = > 1.8.5.5 > = > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- = Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch