| Message ID | 1309749396-8422-1-git-send-email-skeggsb@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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()?
On Wed, 2011-07-06 at 09:38 +0200, Michel Dänzer wrote: > 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()? Heh, ouch. Yes, it was specifically that case I was aiming for however. If nouveau's running on a board without any outputs, it won't call drm_vblank_init(), but it *will* call drm_irq_*. Just avoiding lockdep complaints on module unload. Ben. > >
On Don, 2011-07-07 at 09:10 +1000, Ben Skeggs wrote: > On Wed, 2011-07-06 at 09:38 +0200, Michel Dänzer wrote: > > 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()? > Heh, ouch. > > Yes, it was specifically that case I was aiming for however. If > nouveau's running on a board without any outputs, it won't call > drm_vblank_init(), but it *will* call drm_irq_*. Just avoiding lockdep > complaints on module unload. I see. Reviewed-by: Michel Dänzer <michel@daenzer.net>
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;