From: "Michel Dänzer" <michel@daenzer.net>
To: skeggsb@gmail.com
Cc: Ben Skeggs <bskeggs@redhat.com>, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] drm: make sure drm_vblank_init() has been called before touching vbl_lock
Date: Wed, 06 Jul 2011 09:38:59 +0200 [thread overview]
Message-ID: <1309937939.3713.153.camel@thor.local> (raw)
In-Reply-To: <1309749396-8422-1-git-send-email-skeggsb@gmail.com>
On Mon, 2011-07-04 at 13:16 +1000, skeggsb@gmail.com wrote:
> From: Ben Skeggs <bskeggs@redhat.com>
>
> Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
> ---
> drivers/gpu/drm/drm_irq.c | 15 +++++++++------
> 1 files changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
> index 2022a5c..c3c87a1 100644
> --- a/drivers/gpu/drm/drm_irq.c
> +++ b/drivers/gpu/drm/drm_irq.c
> @@ -397,13 +397,16 @@ int drm_irq_uninstall(struct drm_device *dev)
> /*
> * Wake up any waiters so they don't hang.
> */
> - spin_lock_irqsave(&dev->vbl_lock, irqflags);
> - for (i = 0; i < dev->num_crtcs; i++) {
> - DRM_WAKEUP(&dev->vbl_queue[i]);
> - dev->vblank_enabled[i] = 0;
> - dev->last_vblank[i] = dev->driver->get_vblank_counter(dev, i);
> + if (dev->num_crtcs) {
> + spin_lock_irqsave(&dev->vbl_lock, irqflags);
> + for (i = 0; i < dev->num_crtcs; i++) {
> + DRM_WAKEUP(&dev->vbl_queue[i]);
> + dev->vblank_enabled[i] = 0;
> + dev->last_vblank[i] =
> + dev->driver->get_vblank_counter(dev, i);
> + }
> + spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
> }
> - spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
>
> if (!irq_enabled)
> return -EINVAL;
Makes sense, but according to commit
7a1c2f6c8d8485af5ac6c2a313f6a7162207a4af ('vmwgfx: Enable use of the
vblank system'), the vblank ioctls will also access uninitialized data
if drm_vblank_init() hasn't been called. So, is this just for cases
where drm_irq_uninstall() is called before the driver gets a chance to
call drm_vblank_init()?
--
Earthling Michel Dänzer | http://www.amd.com
Libre software enthusiast | Debian, X and DRI developer
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next prev parent reply other threads:[~2011-07-06 7:39 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-04 3:16 [PATCH] drm: make sure drm_vblank_init() has been called before touching vbl_lock skeggsb
2011-07-06 7:38 ` Michel Dänzer [this message]
2011-07-06 23:10 ` Ben Skeggs
2011-07-07 6:05 ` Michel Dänzer
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