From e9d21d7f5ae1e625f3687d88bb50b00478c533ad Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Thu, 16 Oct 2008 11:31:38 -0700 Subject: [PATCH] i915: Protect vblank IRQ reg access with spinlock 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 Signed-off-by: Eric Anholt Signed-off-by: Dave Airlie --- drivers/gpu/drm/i915/i915_irq.c | 69 +++++++++++++++++++-------------- 1 file changed, 40 insertions(+), 29 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index baae511c785b..671dd79d0aac 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -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) @@ -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; } @@ -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 -- 2.39.5