diff options
| -rw-r--r-- | drivers/gpu/drm/i915/i915_irq.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 0cadafbef41..6290219de6c 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -411,6 +411,12 @@ int i915_enable_vblank(struct drm_device *dev, int pipe) { drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private; unsigned long irqflags; + int pipeconf_reg = (pipe == 0) ? PIPEACONF : PIPEBCONF; + u32 pipeconf; + + pipeconf = I915_READ(pipeconf_reg); + if (!(pipeconf & PIPEACONF_ENABLE)) + return -EINVAL; spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags); if (IS_I965G(dev)) |