diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2011-07-23 12:45:07 +0200 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2011-11-14 09:28:50 +0000 |
| commit | d53dab3ae1a3c6b438738c3792c98ac63f0061f4 (patch) | |
| tree | f4e78aae50cd45ae335dbfed81896c3d965628fe | |
| parent | a7c36fd8c5ee6dcca584137cb81aeefd785a0721 (diff) | |
| download | xen-d53dab3ae1a3c6b438738c3792c98ac63f0061f4.tar.gz | |
drm: Remove utterly bogus preempt_disable() sections
commit 27641c3f (drm/vblank: Add support for precise vblank
timestamping) adds preempt_disable()/enable() around a spin locked
section with the comments:
* Disable preemption, so vblank_time_lock is held as short as
* possible, even under a kernel with PREEMPT_RT patches.
/* Disable preemption while holding vblank_time_lock. Do
* it explicitely to guard against PREEMPT_RT kernel.
Just that this has never been tested on a RT kernel which would have
granted that nonsense with a might_sleep() warning because
dev->vblank_time_lock is converted to a "sleeping" spinlock on RT.
So this is activly wrong on RT and superflous on mainline. Remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
| -rw-r--r-- | drivers/gpu/drm/drm_irq.c | 9 |
1 files changed, 0 insertions, 9 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 68b756253f9f2..44a5d0ad8b7c5 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -110,10 +110,7 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc) /* Prevent vblank irq processing while disabling vblank irqs, * so no updates of timestamps or count can happen after we've * disabled. Needed to prevent races in case of delayed irq's. - * Disable preemption, so vblank_time_lock is held as short as - * possible, even under a kernel with PREEMPT_RT patches. */ - preempt_disable(); spin_lock_irqsave(&dev->vblank_time_lock, irqflags); dev->driver->disable_vblank(dev, crtc); @@ -164,7 +161,6 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc) clear_vblank_timestamps(dev, crtc); spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags); - preempt_enable(); } static void vblank_disable_fn(unsigned long arg) @@ -889,10 +885,6 @@ int drm_vblank_get(struct drm_device *dev, int crtc) spin_lock_irqsave(&dev->vbl_lock, irqflags); /* Going from 0->1 means we have to enable interrupts again */ if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) { - /* Disable preemption while holding vblank_time_lock. Do - * it explicitely to guard against PREEMPT_RT kernel. - */ - preempt_disable(); spin_lock_irqsave(&dev->vblank_time_lock, irqflags2); if (!dev->vblank_enabled[crtc]) { /* Enable vblank irqs under vblank_time_lock protection. @@ -912,7 +904,6 @@ int drm_vblank_get(struct drm_device *dev, int crtc) } } spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2); - preempt_enable(); } else { if (!dev->vblank_enabled[crtc]) { atomic_dec(&dev->vblank_refcount[crtc]); |