[Intel-gfx] [PATCH] drm: Remove two leaks of vblank reference count in error paths.

Eric Anholt eric at anholt.net
Fri Oct 17 23:56:26 CEST 2008


On Fri, 2008-10-17 at 14:53 -0700, Keith Packard wrote:
> On Fri, 2008-10-17 at 11:47 -0700, Eric Anholt wrote:
> > If the failing paths were hit, the vblank IRQ would never get turned off
> > again.
> 
> > 
> > Signed-off-by: Eric Anholt <eric at anholt.net>
> > ---
> >  drivers/gpu/drm/drm_irq.c       |    5 ++++-
> >  drivers/gpu/drm/i915/i915_irq.c |    1 +
> >  2 files changed, 5 insertions(+), 1 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
> > index d0c13d9..81739c7 100644
> > --- a/drivers/gpu/drm/drm_irq.c
> > +++ b/drivers/gpu/drm/drm_irq.c
> > @@ -597,11 +597,14 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
> >  			goto done;
> >  		}
> >  
> > +		/* Get a refcount on the vblank, which will be released by
> > +		 * drm_vbl_send_signals().
> > +		 */
> >  		ret = drm_vblank_get(dev, crtc);
> >  		if (ret) {
> >  			drm_free(vbl_sig, sizeof(struct drm_vbl_sig),
> >  				 DRM_MEM_DRIVER);
> > -			return ret;
> > +			goto done;
> >  		}
> 
> This is a failure in drm_vblank_get, which should not be matched with
> drm_vblank_put

This is to match the drm_vblank_get in the function above that hunk.

(We actually can't hit this error path currently as drm_vblank_get
always returns 0,  but it should still be fixed).

> >  		atomic_inc(&dev->vbl_signal_pending);
> > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> > index 6d0ae92..3658a04 100644
> > --- a/drivers/gpu/drm/i915/i915_irq.c
> > +++ b/drivers/gpu/drm/i915/i915_irq.c
> > @@ -768,6 +768,7 @@ int i915_vblank_swap(struct drm_device *dev, void *data,
> >  		    vbl_swap->plane == plane &&
> >  		    vbl_swap->sequence == swap->sequence) {
> >  			spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
> > +			drm_vblank_put(dev, pipe);
> >  			DRM_DEBUG("Already scheduled\n");
> >  			return 0;
> >  		}
> 
> This is in the vblank rework patch I sent out last night, but it's nice
> to have it split out.


-- 
Eric Anholt
eric at anholt.net                         eric.anholt at intel.com


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