From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH 4/5] drm: Allow reenabling of vblank interrupts even if refcount>0 Date: Tue, 4 Mar 2014 10:16:02 +0100 Message-ID: <20140304091602.GR17001@phenom.ffwll.local> References: <1393009415-27651-1-git-send-email-ville.syrjala@linux.intel.com> <1393009415-27651-5-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: Content-Disposition: inline In-Reply-To: <1393009415-27651-5-git-send-email-ville.syrjala@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org To: ville.syrjala@linux.intel.com Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Fri, Feb 21, 2014 at 09:03:34PM +0200, ville.syrjala@linux.intel.com wro= te: > From: Ville Syrj=E4l=E4 > = > If someone holds a vblank reference across the modeset, and after/during > the modeset someone tries to grab a vblank reference, the current code > won't re-enable the vblank interrupts. That's not good, so instead allow > the driver to choose whether drm_vblank_get() should always enable the > interrupts regardless of the refcount. > = > Combined with the drm_vblank_off/drm_vblank_on reject mechanism, this > can also be used to allow drivers to use vblank interrupts during > modeset, whether or not someone is currently holding a vblank reference. > = > Signed-off-by: Ville Syrj=E4l=E4 > --- > drivers/gpu/drm/drm_irq.c | 3 ++- > include/drm/drmP.h | 6 ++++++ > 2 files changed, 8 insertions(+), 1 deletion(-) > = > diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c > index 6e5d820..d613b6f 100644 > --- a/drivers/gpu/drm/drm_irq.c > +++ b/drivers/gpu/drm/drm_irq.c > @@ -897,7 +897,8 @@ int drm_vblank_get(struct drm_device *dev, int crtc) > } > = > /* Going from 0->1 means we have to enable interrupts again */ > - if (atomic_add_return(1, &dev->vblank[crtc].refcount) =3D=3D 1) { > + if (atomic_add_return(1, &dev->vblank[crtc].refcount) =3D=3D 1 || > + dev->vblank_always_enable_on_get) { > spin_lock(&dev->vblank_time_lock); > if (!dev->vblank[crtc].enabled) { > /* Enable vblank irqs under vblank_time_lock protection. > diff --git a/include/drm/drmP.h b/include/drm/drmP.h > index ee40483..3eca0ee 100644 > --- a/include/drm/drmP.h > +++ b/include/drm/drmP.h > @@ -1156,6 +1156,12 @@ struct drm_device { > */ > bool vblank_disable_allowed; > = > + /* > + * Should a non-rejected drm_vblank_get() always enable the > + * vblank interrupt regardless of the current refcount? > + */ > + bool vblank_always_enable_on_get; Nack for this hack. Why can't drm_vblank_on not just re-enable the vblank interrupt if we still have a vblank reference? -Daniel > + > /* array of size num_crtcs */ > struct drm_vblank_crtc *vblank; > = > -- = > 1.8.3.2 > = > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel -- = Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch