From: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915: don't set unpin_work if vblank_get fails
Date: Mon, 29 Aug 2011 09:45:28 -0700 [thread overview]
Message-ID: <20110829094528.2b176630@jbarnes-desktop> (raw)
In-Reply-To: <20110829094452.7a5adf03@jbarnes-desktop>
On Mon, 29 Aug 2011 09:44:52 -0700
Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> On Mon, 22 Aug 2011 11:05:31 -0700
> Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
>
> > This fixes a race where we may try to finish a page flip and decrement
> > the refcount even if our vblank_get failed and we ended up with a
> > spurious flip pending interrupt.
> >
> > Fixes https://bugs.freedesktop.org/show_bug.cgi?id=34211.
> >
> > Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
>
> Updated patch. Though now I've lost track of the outstanding
> issues... IIRC we still have another race here, but it's unrelated to
> the one in the bug report.
With patch...
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2319f62..9cd523b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6896,11 +6896,16 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
work->old_fb_obj = intel_fb->obj;
INIT_WORK(&work->work, intel_unpin_work_fn);
+ ret = drm_vblank_get(dev, intel_crtc->pipe);
+ if (ret)
+ goto free_work;
+
/* We borrow the event spin lock for protecting unpin_work */
spin_lock_irqsave(&dev->event_lock, flags);
if (intel_crtc->unpin_work) {
spin_unlock_irqrestore(&dev->event_lock, flags);
kfree(work);
+ drm_vblank_put(dev, intel_crtc->pipe);
DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
return -EBUSY;
@@ -6919,10 +6924,6 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
crtc->fb = fb;
- ret = drm_vblank_get(dev, intel_crtc->pipe);
- if (ret)
- goto cleanup_objs;
-
work->pending_flip_obj = obj;
work->enable_stall_check = true;
@@ -6945,7 +6946,6 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
cleanup_pending:
atomic_sub(1 << intel_crtc->plane, &work->old_fb_obj->pending_flip);
-cleanup_objs:
drm_gem_object_unreference(&work->old_fb_obj->base);
drm_gem_object_unreference(&obj->base);
mutex_unlock(&dev->struct_mutex);
@@ -6954,6 +6954,8 @@ cleanup_objs:
intel_crtc->unpin_work = NULL;
spin_unlock_irqrestore(&dev->event_lock, flags);
+ drm_vblank_put(dev, intel_crtc->pipe);
+free_work:
kfree(work);
return ret;
next prev parent reply other threads:[~2011-08-29 16:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-22 18:05 [PATCH] drm/i915: don't set unpin_work if vblank_get fails Jesse Barnes
2011-08-22 18:45 ` Keith Packard
2011-08-29 16:44 ` Jesse Barnes
2011-08-29 16:45 ` Jesse Barnes [this message]
2011-09-20 4:04 ` Keith Packard
2011-11-11 20:36 ` Jesse Barnes
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