From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH 4/5] drm: Allow reenabling of vblank interrupts even if refcount>0 Date: Wed, 5 Mar 2014 14:33:00 +0200 Message-ID: <20140305123300.GQ3852@intel.com> References: <1393009415-27651-1-git-send-email-ville.syrjala@linux.intel.com> <1393009415-27651-5-git-send-email-ville.syrjala@linux.intel.com> <20140304091602.GR17001@phenom.ffwll.local> 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: <20140304091602.GR17001@phenom.ffwll.local> 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: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Tue, Mar 04, 2014 at 10:16:02AM +0100, Daniel Vetter wrote: > On Fri, Feb 21, 2014 at 09:03:34PM +0200, ville.syrjala@linux.intel.com w= rote: > > 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? Hmm. Yeah that seems like a nicer way to go about it. -- = Ville Syrj=E4l=E4 Intel OTC