diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2015-09-14 22:43:48 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-09-24 21:14:22 +0300 |
| commit | facfb062e8c958f321c366c6ea3d98db899a4c6e (patch) | |
| tree | d2c7cd8b72d88ac31325e228fc0bdc8335023689 /drivers/gpu/drm/drm_irq.c | |
| parent | a6e610dcce3c8cbd5217527a089c8811d4412184 (diff) | |
| download | linux-facfb062e8c958f321c366c6ea3d98db899a4c6e.tar.xz | |
drm: Limit the number of .get_vblank_counter() retries
Pontential infinite loops in the vblank code are a bad idea. Add some
limits.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/drm_irq.c')
| -rw-r--r-- | drivers/gpu/drm/drm_irq.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 0353224e0601..93fe582b5ca3 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -127,6 +127,7 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe, u32 cur_vblank, diff; bool rc; struct timeval t_vblank; + int count = DRM_TIMESTAMP_MAXRETRIES; /* * Interrupts were disabled prior to this call, so deal with counter @@ -143,7 +144,7 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe, do { cur_vblank = dev->driver->get_vblank_counter(dev, pipe); rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, flags); - } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe)); + } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0); /* Deal with counter wrap */ diff = cur_vblank - vblank->last; @@ -914,6 +915,7 @@ u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe, struct timeval *vblanktime) { struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + int count = DRM_TIMESTAMP_MAXRETRIES; u32 cur_vblank; if (WARN_ON(pipe >= dev->num_crtcs)) @@ -929,7 +931,7 @@ u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe, smp_rmb(); *vblanktime = vblanktimestamp(dev, pipe, cur_vblank); smp_rmb(); - } while (cur_vblank != vblank->count); + } while (cur_vblank != vblank->count && --count > 0); return cur_vblank; } |