| Message ID | 20200722010527.52293-1-xuqiang36@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [-next] gpu: drm: Fix spinlock vblank_time_lock use error. | expand |
On Wed, Jul 22, 2020 at 01:05:27AM +0000, Xu Qiang wrote: > The drm_handle_vblank function is in the interrupt context. > Therefore, the spin lock vblank_time_lock is obtained > from the interrupt context. > > Cc: <stable@vger.kernel.org> > Signed-off-by: Xu Qiang <xuqiang36@huawei.com> > --- > drivers/gpu/drm/drm_vblank.c | 17 ++++++++++------- > 1 file changed, 10 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c > index f402c75b9d34..4ca63ff33a43 100644 > --- a/drivers/gpu/drm/drm_vblank.c > +++ b/drivers/gpu/drm/drm_vblank.c > @@ -229,10 +229,11 @@ static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe > { > u32 cur_vblank; > bool rc; > + unsigned long irqflags; > ktime_t t_vblank; > int count = DRM_TIMESTAMP_MAXRETRIES; > > - spin_lock(&dev->vblank_time_lock); > + spin_lock_irqsave(&dev->vblank_time_lock, irqflags); Nak. This is always called with interrupts off, so no point on wasting time saving/restoring the flags. And it's the same situation for all the other cases you have below. > > /* > * sample the current counter to avoid random jumps > @@ -257,7 +258,7 @@ static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe > */ > store_vblank(dev, pipe, 1, t_vblank, cur_vblank); > > - spin_unlock(&dev->vblank_time_lock); > + spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags); > } > > /* > @@ -1106,11 +1107,12 @@ static int __enable_vblank(struct drm_device *dev, unsigned int pipe) > static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe) > { > struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; > + unsigned long irqflags; > int ret = 0; > > assert_spin_locked(&dev->vbl_lock); > > - spin_lock(&dev->vblank_time_lock); > + spin_lock_irqsave(&dev->vblank_time_lock, irqflags); > > if (!vblank->enabled) { > /* > @@ -1136,7 +1138,7 @@ static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe) > } > } > > - spin_unlock(&dev->vblank_time_lock); > + spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags); > > return ret; > } > @@ -1917,6 +1919,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) > { > struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; > unsigned long irqflags; > + unsigned long irqflags_vblank; > bool disable_irq; > > if (drm_WARN_ON_ONCE(dev, !drm_dev_has_vblank(dev))) > @@ -1931,18 +1934,18 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) > * vblank enable/disable, as this would cause inconsistent > * or corrupted timestamps and vblank counts. > */ > - spin_lock(&dev->vblank_time_lock); > + spin_lock_irqsave(&dev->vblank_time_lock, irqflags_vblank); > > /* Vblank irq handling disabled. Nothing to do. */ > if (!vblank->enabled) { > - spin_unlock(&dev->vblank_time_lock); > + spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags_vblank); > spin_unlock_irqrestore(&dev->event_lock, irqflags); > return false; > } > > drm_update_vblank_count(dev, pipe, true); > > - spin_unlock(&dev->vblank_time_lock); > + spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags_vblank); > > wake_up(&vblank->queue); > > -- > 2.25.0 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index f402c75b9d34..4ca63ff33a43 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -229,10 +229,11 @@ static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe { u32 cur_vblank; bool rc; + unsigned long irqflags; ktime_t t_vblank; int count = DRM_TIMESTAMP_MAXRETRIES; - spin_lock(&dev->vblank_time_lock); + spin_lock_irqsave(&dev->vblank_time_lock, irqflags); /* * sample the current counter to avoid random jumps @@ -257,7 +258,7 @@ static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe */ store_vblank(dev, pipe, 1, t_vblank, cur_vblank); - spin_unlock(&dev->vblank_time_lock); + spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags); } /* @@ -1106,11 +1107,12 @@ static int __enable_vblank(struct drm_device *dev, unsigned int pipe) static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe) { struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + unsigned long irqflags; int ret = 0; assert_spin_locked(&dev->vbl_lock); - spin_lock(&dev->vblank_time_lock); + spin_lock_irqsave(&dev->vblank_time_lock, irqflags); if (!vblank->enabled) { /* @@ -1136,7 +1138,7 @@ static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe) } } - spin_unlock(&dev->vblank_time_lock); + spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags); return ret; } @@ -1917,6 +1919,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) { struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; unsigned long irqflags; + unsigned long irqflags_vblank; bool disable_irq; if (drm_WARN_ON_ONCE(dev, !drm_dev_has_vblank(dev))) @@ -1931,18 +1934,18 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) * vblank enable/disable, as this would cause inconsistent * or corrupted timestamps and vblank counts. */ - spin_lock(&dev->vblank_time_lock); + spin_lock_irqsave(&dev->vblank_time_lock, irqflags_vblank); /* Vblank irq handling disabled. Nothing to do. */ if (!vblank->enabled) { - spin_unlock(&dev->vblank_time_lock); + spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags_vblank); spin_unlock_irqrestore(&dev->event_lock, irqflags); return false; } drm_update_vblank_count(dev, pipe, true); - spin_unlock(&dev->vblank_time_lock); + spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags_vblank); wake_up(&vblank->queue);
The drm_handle_vblank function is in the interrupt context. Therefore, the spin lock vblank_time_lock is obtained from the interrupt context. Cc: <stable@vger.kernel.org> Signed-off-by: Xu Qiang <xuqiang36@huawei.com> --- drivers/gpu/drm/drm_vblank.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)