Skip to content

Commit

Permalink
i915: Protect vblank IRQ reg access with spinlock
Browse files Browse the repository at this point in the history 
This uses the same spinlock as the user_irq code as it shares the same
register, ensuring that interrupt registers are updated atomically.

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
  • Loading branch information
Keith Packard authored and Dave Airlie committed Oct 23, 2008
1 parent 4b40893 commit e9d21d7
Showing 1 changed file with 40 additions and 29 deletions.
69 changes: 40 additions & 29 deletions drivers/gpu/drm/i915/i915_irq.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -481,22 +481,24 @@ static int i915_emit_irq(struct drm_device * dev)
void i915_user_irq_get(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
unsigned long irqflags;

spin_lock(&dev_priv->user_irq_lock);
spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
if (dev->irq_enabled && (++dev_priv->user_irq_refcount == 1))
i915_enable_irq(dev_priv, I915_USER_INTERRUPT);
spin_unlock(&dev_priv->user_irq_lock);
spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
}

void i915_user_irq_put(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
unsigned long irqflags;

spin_lock(&dev_priv->user_irq_lock);
spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
BUG_ON(dev->irq_enabled && dev_priv->user_irq_refcount <= 0);
if (dev->irq_enabled && (--dev_priv->user_irq_refcount == 0))
i915_disable_irq(dev_priv, I915_USER_INTERRUPT);
spin_unlock(&dev_priv->user_irq_lock);
spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
}

static int i915_wait_irq(struct drm_device * dev, int irq_nr)
Expand Down Expand Up @@ -584,33 +586,37 @@ int i915_enable_vblank(struct drm_device *dev, int plane)
int pipe = i915_get_pipe(dev, plane);
u32 pipestat_reg = 0;
u32 pipestat;
u32 interrupt = 0;
unsigned long irqflags;

switch (pipe) {
case 0:
pipestat_reg = PIPEASTAT;
i915_enable_irq(dev_priv, I915_DISPLAY_PIPE_A_EVENT_INTERRUPT);
interrupt = I915_DISPLAY_PIPE_A_EVENT_INTERRUPT;
break;
case 1:
pipestat_reg = PIPEBSTAT;
i915_enable_irq(dev_priv, I915_DISPLAY_PIPE_B_EVENT_INTERRUPT);
interrupt = I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
break;
default:
DRM_ERROR("tried to enable vblank on non-existent pipe %d\n",
pipe);
break;
return 0;
}

if (pipestat_reg) {
pipestat = I915_READ(pipestat_reg);
if (IS_I965G(dev))
pipestat |= PIPE_START_VBLANK_INTERRUPT_ENABLE;
else
pipestat |= PIPE_VBLANK_INTERRUPT_ENABLE;
/* Clear any stale interrupt status */
pipestat |= (PIPE_START_VBLANK_INTERRUPT_STATUS |
PIPE_VBLANK_INTERRUPT_STATUS);
I915_WRITE(pipestat_reg, pipestat);
}
spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
pipestat = I915_READ(pipestat_reg);
if (IS_I965G(dev))
pipestat |= PIPE_START_VBLANK_INTERRUPT_ENABLE;
else
pipestat |= PIPE_VBLANK_INTERRUPT_ENABLE;
/* Clear any stale interrupt status */
pipestat |= (PIPE_START_VBLANK_INTERRUPT_STATUS |
PIPE_VBLANK_INTERRUPT_STATUS);
I915_WRITE(pipestat_reg, pipestat);
(void) I915_READ(pipestat_reg); /* Posting read */
i915_enable_irq(dev_priv, interrupt);
spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);

return 0;
}
Expand All @@ -621,31 +627,36 @@ void i915_disable_vblank(struct drm_device *dev, int plane)
int pipe = i915_get_pipe(dev, plane);
u32 pipestat_reg = 0;
u32 pipestat;
u32 interrupt = 0;
unsigned long irqflags;

switch (pipe) {
case 0:
pipestat_reg = PIPEASTAT;
i915_disable_irq(dev_priv, I915_DISPLAY_PIPE_A_EVENT_INTERRUPT);
interrupt = I915_DISPLAY_PIPE_A_EVENT_INTERRUPT;
break;
case 1:
pipestat_reg = PIPEBSTAT;
i915_disable_irq(dev_priv, I915_DISPLAY_PIPE_B_EVENT_INTERRUPT);
interrupt = I915_DISPLAY_PIPE_B_EVENT_INTERRUPT;
break;
default:
DRM_ERROR("tried to disable vblank on non-existent pipe %d\n",
pipe);
return;
break;
}

if (pipestat_reg) {
pipestat = I915_READ(pipestat_reg);
pipestat &= ~(PIPE_START_VBLANK_INTERRUPT_ENABLE |
PIPE_VBLANK_INTERRUPT_ENABLE);
/* Clear any stale interrupt status */
pipestat |= (PIPE_START_VBLANK_INTERRUPT_STATUS |
PIPE_VBLANK_INTERRUPT_STATUS);
I915_WRITE(pipestat_reg, pipestat);
}
spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
i915_disable_irq(dev_priv, interrupt);
pipestat = I915_READ(pipestat_reg);
pipestat &= ~(PIPE_START_VBLANK_INTERRUPT_ENABLE |
PIPE_VBLANK_INTERRUPT_ENABLE);
/* Clear any stale interrupt status */
pipestat |= (PIPE_START_VBLANK_INTERRUPT_STATUS |
PIPE_VBLANK_INTERRUPT_STATUS);
I915_WRITE(pipestat_reg, pipestat);
(void) I915_READ(pipestat_reg); /* Posting read */
spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
}

/* Set the vblank monitor pipe
Expand Down

0 comments on commit e9d21d7

Please sign in to comment.