From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH 2/6] drm/i915: Don't wait for page flips if there was GPU reset Date: Wed, 13 Feb 2013 16:23:27 +0100 Message-ID: <20130213152326.GJ5813@phenom.ffwll.local> References: <1359476018-31274-1-git-send-email-ville.syrjala@linux.intel.com> <1359476018-31274-3-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-wi0-f176.google.com (mail-wi0-f176.google.com [209.85.212.176]) by gabe.freedesktop.org (Postfix) with ESMTP id 6C0E6E66DF for ; Wed, 13 Feb 2013 07:21:12 -0800 (PST) Received: by mail-wi0-f176.google.com with SMTP id hm14so5834792wib.15 for ; Wed, 13 Feb 2013 07:21:11 -0800 (PST) Content-Disposition: inline In-Reply-To: <1359476018-31274-3-git-send-email-ville.syrjala@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: ville.syrjala@linux.intel.com Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Tue, Jan 29, 2013 at 06:13:34PM +0200, ville.syrjala@linux.intel.com wro= te: > From: Ville Syrj=E4l=E4 > = > If a GPU reset occurs while a page flip has been submitted to the ring, > the flip will never complete once the ring has been reset. > = > The GPU reset can be detected by sampling the reset_counter before the > flip is submitted, and then while waiting for the flip, the sampled > counter is compared with the current reset_counter value. > = > Signed-off-by: Ville Syrj=E4l=E4 > --- > drivers/gpu/drm/i915/intel_display.c | 14 +++++++++++++- > drivers/gpu/drm/i915/intel_drv.h | 3 +++ > 2 files changed, 16 insertions(+), 1 deletion(-) > = > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/= intel_display.c > index 4097118..e348a68 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -2862,10 +2862,12 @@ static bool intel_crtc_has_pending_flip(struct dr= m_crtc *crtc) > { > struct drm_device *dev =3D crtc->dev; > struct drm_i915_private *dev_priv =3D dev->dev_private; > + struct intel_crtc *intel_crtc =3D to_intel_crtc(crtc); > unsigned long flags; > bool pending; > = > - if (i915_reset_in_progress(&dev_priv->gpu_error)) > + if (i915_reset_in_progress(&dev_priv->gpu_error) || > + intel_crtc->reset_counter !=3D atomic_read(&dev_priv->gpu_error.res= et_counter)) > return false; > = > spin_lock_irqsave(&dev->event_lock, flags); > @@ -6912,6 +6914,8 @@ static int intel_gen2_queue_flip(struct drm_device = *dev, > if (ret) > goto err_unpin; > = > + intel_crtc->reset_counter =3D atomic_read(&dev_priv->gpu_error.reset_co= unter); Ok no bikeshed about ->reset_counter, but a different one: Why does this need to be in the per-gen callback? Can't we just grab this before we call down into these callbacks? Imo races wrt the reset/hang code don't matter that much as long as we don't wait forever for a pageflip which won't happen. Hanging the gpu concurrently to pageflipping is undefined anyway right now ... -Daniel > + > /* Can't queue multiple flips, so wait for the previous > * one to finish before executing the next. > */ > @@ -6956,6 +6960,8 @@ static int intel_gen3_queue_flip(struct drm_device = *dev, > if (ret) > goto err_unpin; > = > + intel_crtc->reset_counter =3D atomic_read(&dev_priv->gpu_error.reset_co= unter); > + > if (intel_crtc->plane) > flip_mask =3D MI_WAIT_FOR_PLANE_B_FLIP; > else > @@ -6997,6 +7003,8 @@ static int intel_gen4_queue_flip(struct drm_device = *dev, > if (ret) > goto err_unpin; > = > + intel_crtc->reset_counter =3D atomic_read(&dev_priv->gpu_error.reset_co= unter); > + > /* i965+ uses the linear or tiled offsets from the > * Display Registers (which do not change across a page-flip) > * so we need only reprogram the base address. > @@ -7045,6 +7053,8 @@ static int intel_gen6_queue_flip(struct drm_device = *dev, > if (ret) > goto err_unpin; > = > + intel_crtc->reset_counter =3D atomic_read(&dev_priv->gpu_error.reset_co= unter); > + > intel_ring_emit(ring, MI_DISPLAY_FLIP | > MI_DISPLAY_FLIP_PLANE(intel_crtc->plane)); > intel_ring_emit(ring, fb->pitches[0] | obj->tiling_mode); > @@ -7111,6 +7121,8 @@ static int intel_gen7_queue_flip(struct drm_device = *dev, > if (ret) > goto err_unpin; > = > + intel_crtc->reset_counter =3D atomic_read(&dev_priv->gpu_error.reset_co= unter); > + > intel_ring_emit(ring, MI_DISPLAY_FLIP_I915 | plane_bit); > intel_ring_emit(ring, (fb->pitches[0] | obj->tiling_mode)); > intel_ring_emit(ring, obj->gtt_offset + intel_crtc->dspaddr_offset); > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/inte= l_drv.h > index fcdfe42..a5521d9 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -235,6 +235,9 @@ struct intel_crtc { > /* We can share PLLs across outputs if the timings match */ > struct intel_pch_pll *pch_pll; > uint32_t ddi_pll_sel; > + > + /* reset counter value when the last flip was submitted */ > + unsigned int reset_counter; > }; > = > struct intel_plane { > -- = > 1.7.12.4 > = > _______________________________________________ > 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