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-rw-r--r--drivers/gpu/drm/i915/i915_irq.c108
1 files changed, 61 insertions, 47 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index ca3ed183390..654d42fabec 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -168,69 +168,83 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
{
struct drm_device *dev = (struct drm_device *) arg;
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
- u32 iir;
- u32 pipea_stats = 0, pipeb_stats = 0;
+ u32 iir, new_iir;
+ u32 pipea_stats, pipeb_stats;
int vblank = 0;
unsigned long irqflags;
- spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
atomic_inc(&dev_priv->irq_received);
- if (dev->pdev->msi_enabled)
- I915_WRITE(IMR, ~0);
iir = I915_READ(IIR);
- if (iir == 0) {
- if (dev->pdev->msi_enabled) {
- I915_WRITE(IMR, dev_priv->irq_mask_reg);
- (void) I915_READ(IMR);
- }
- spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
+ if (iir == 0)
return IRQ_NONE;
- }
-
- /*
- * Clear the PIPE(A|B)STAT regs before the IIR
- */
- if (iir & I915_DISPLAY_PIPE_A_EVENT_INTERRUPT) {
- pipea_stats = I915_READ(PIPEASTAT);
- I915_WRITE(PIPEASTAT, pipea_stats);
- }
- if (iir & I915_DISPLAY_PIPE_B_EVENT_INTERRUPT) {
- pipeb_stats = I915_READ(PIPEBSTAT);
- I915_WRITE(PIPEBSTAT, pipeb_stats);
- }
+ do {
+ pipea_stats = 0;
+ pipeb_stats = 0;
+ /*
+ * Clear the PIPE(A|B)STAT regs before the IIR
+ */
+ if (iir & I915_DISPLAY_PIPE_A_EVENT_INTERRUPT) {
+ spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
+ pipea_stats = I915_READ(PIPEASTAT);
+ I915_WRITE(PIPEASTAT, pipea_stats);
+ spin_unlock_irqrestore(&dev_priv->user_irq_lock,
+ irqflags);
+ }
- I915_WRITE(IIR, iir);
- if (dev->pdev->msi_enabled)
- I915_WRITE(IMR, dev_priv->irq_mask_reg);
- (void) I915_READ(IIR); /* Flush posted writes */
+ if (iir & I915_DISPLAY_PIPE_B_EVENT_INTERRUPT) {
+ spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
+ pipeb_stats = I915_READ(PIPEBSTAT);
+ I915_WRITE(PIPEBSTAT, pipeb_stats);
+ spin_unlock_irqrestore(&dev_priv->user_irq_lock,
+ irqflags);
+ }
- spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
+ I915_WRITE(IIR, iir);
+ new_iir = I915_READ(IIR); /* Flush posted writes */
- if (dev_priv->sarea_priv)
- dev_priv->sarea_priv->last_dispatch =
- READ_BREADCRUMB(dev_priv);
+ if (dev_priv->sarea_priv)
+ dev_priv->sarea_priv->last_dispatch =
+ READ_BREADCRUMB(dev_priv);
- if (iir & I915_USER_INTERRUPT) {
- dev_priv->mm.irq_gem_seqno = i915_get_gem_seqno(dev);
- DRM_WAKEUP(&dev_priv->irq_queue);
- }
+ if (iir & I915_USER_INTERRUPT) {
+ dev_priv->mm.irq_gem_seqno = i915_get_gem_seqno(dev);
+ DRM_WAKEUP(&dev_priv->irq_queue);
+ }
- if (pipea_stats & I915_VBLANK_INTERRUPT_STATUS) {
- vblank++;
- drm_handle_vblank(dev, 0);
- }
+ if (pipea_stats & I915_VBLANK_INTERRUPT_STATUS) {
+ vblank++;
+ drm_handle_vblank(dev, 0);
+ }
- if (pipeb_stats & I915_VBLANK_INTERRUPT_STATUS) {
- vblank++;
- drm_handle_vblank(dev, 1);
- }
+ if (pipeb_stats & I915_VBLANK_INTERRUPT_STATUS) {
+ vblank++;
+ drm_handle_vblank(dev, 1);
+ }
- if ((pipeb_stats & I915_LEGACY_BLC_EVENT_STATUS) ||
- (iir & I915_ASLE_INTERRUPT))
- opregion_asle_intr(dev);
+ if ((pipeb_stats & I915_LEGACY_BLC_EVENT_STATUS) ||
+ (iir & I915_ASLE_INTERRUPT))
+ opregion_asle_intr(dev);
+
+ /* With MSI, interrupts are only generated when iir
+ * transitions from zero to nonzero. If another bit got
+ * set while we were handling the existing iir bits, then
+ * we would never get another interrupt.
+ *
+ * This is fine on non-MSI as well, as if we hit this path
+ * we avoid exiting the interrupt handler only to generate
+ * another one.
+ *
+ * Note that for MSI this could cause a stray interrupt report
+ * if an interrupt landed in the time between writing IIR and
+ * the posting read. This should be rare enough to never
+ * trigger the 99% of 100,000 interrupts test for disabling
+ * stray interrupts.
+ */
+ iir = new_iir;
+ } while (iir != 0);
return IRQ_HANDLED;
}