From 71e0ffa599f54058d9b8724b4b14d0486751681d Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Thu, 8 Jan 2009 10:42:15 -0800 Subject: [PATCH] drm/i915: don't enable vblanks on disabled pipes In some cases userland may be confused and try to wait on vblank events from pipes that aren't actually enabled. We shouldn't allow this, so return -EINVAL if the pipe isn't on. Signed-off-by: Jesse Barnes Signed-off-by: Eric Anholt Signed-off-by: Dave Airlie --- drivers/gpu/drm/i915/i915_irq.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 0cadafbef411..6290219de6c8 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))