@@ -95,6 +95,8 @@ static void i915_hpd_irq_setup(struct drm_device *dev);
static void
ironlake_enable_display_irq(drm_i915_private_t *dev_priv, u32 mask)
{
+ assert_spin_locked(&dev_priv->irq_lock);
+
if ((dev_priv->irq_mask & mask) != 0) {
dev_priv->irq_mask &= ~mask;
I915_WRITE(DEIMR, dev_priv->irq_mask);
@@ -105,6 +107,8 @@ ironlake_enable_display_irq(drm_i915_private_t *dev_priv, u32 mask)
static void
ironlake_disable_display_irq(drm_i915_private_t *dev_priv, u32 mask)
{
+ assert_spin_locked(&dev_priv->irq_lock);
+
if ((dev_priv->irq_mask & mask) != mask) {
dev_priv->irq_mask |= mask;
I915_WRITE(DEIMR, dev_priv->irq_mask);
@@ -1218,8 +1222,11 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
/* On Haswell, also mask ERR_INT because we don't want to risk
* generating "unclaimed register" interrupts from inside the interrupt
* handler. */
- if (IS_HASWELL(dev))
+ if (IS_HASWELL(dev)) {
+ spin_lock(&dev_priv->irq_lock);
ironlake_disable_display_irq(dev_priv, DE_ERR_INT_IVB);
+ spin_unlock(&dev_priv->irq_lock);
+ }
gt_iir = I915_READ(GTIIR);
if (gt_iir) {
@@ -1272,8 +1279,11 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg)
ret = IRQ_HANDLED;
}
- if (IS_HASWELL(dev) && ivb_can_enable_err_int(dev))
+ if (IS_HASWELL(dev) && ivb_can_enable_err_int(dev)) {
+ spin_lock(&dev_priv->irq_lock);
ironlake_enable_display_irq(dev_priv, DE_ERR_INT_IVB);
+ spin_unlock(&dev_priv->irq_lock);
+ }
I915_WRITE(DEIER, de_ier);
POSTING_READ(DEIER);
@@ -2633,6 +2643,8 @@ static void ibx_irq_postinstall(struct drm_device *dev)
static int ironlake_irq_postinstall(struct drm_device *dev)
{
+ unsigned long irqflags;
+
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
/* enable kind of interrupts always enabled */
u32 display_mask = DE_MASTER_IRQ_CONTROL | DE_GSE | DE_PCH_EVENT |
@@ -2671,7 +2683,13 @@ static int ironlake_irq_postinstall(struct drm_device *dev)
/* Clear & enable PCU event interrupts */
I915_WRITE(DEIIR, DE_PCU_EVENT);
I915_WRITE(DEIER, I915_READ(DEIER) | DE_PCU_EVENT);
+
+ /* spinlocking not required here for correctness since interrupt
+ * setup is guaranteed to run in single-threaded context. But we
+ * need it to make the assert_spin_locked happy. */
+ spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
ironlake_enable_display_irq(dev_priv, DE_PCU_EVENT);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
}
return 0;
The haswell unclaimed register handling code forgot to take the spinlock. Since this is in the context of the non-rentrant interupt handler and we only have one interrupt handler it is sufficient to just grab the spinlock - we do not need to exclude any other interrupts from running on the same cpu. To prevent such gaffles in the future sprinkle assert_spin_locked over these functions. Unfornately this requires us to hold the spinlock in the ironlake postinstall hook where it is not strictly required: Currently that is run in single-threaded context and with userspace exlcuded from running concurrent ioctls. Add a comment explaining this. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> --- drivers/gpu/drm/i915/i915_irq.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-)