drm/i915: streamline hsw_pm_irq_handler

The if (pm_iir & ~GEN6_PM_RPS_EVENTS) check was redunandant. Otoh
adding a check for rps events allows us to avoid the spinlock grabbing
for VECS interrupts.

v2: Drop misplaced hunk which now moved to the right patch.

Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index a7c0a730a6e1d0167b77c4bd7c426aeec1013c0a..d4af11541287ecfc4fac4b49f42fe2e94f6be449 100644 (file)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -963,25 +963,23 @@ static void dp_aux_irq_handler(struct drm_device *dev)
 static void hsw_pm_irq_handler(struct drm_i915_private *dev_priv,
                               u32 pm_iir)
 {
-       spin_lock(&dev_priv->rps.lock);
-       dev_priv->rps.pm_iir |= pm_iir & GEN6_PM_RPS_EVENTS;
-       if (dev_priv->rps.pm_iir) {
+       if (pm_iir & GEN6_PM_RPS_EVENTS) {
+               spin_lock(&dev_priv->rps.lock);
+               dev_priv->rps.pm_iir |= pm_iir & GEN6_PM_RPS_EVENTS;
                I915_WRITE(GEN6_PMIMR, dev_priv->rps.pm_iir);
                /* never want to mask useful interrupts. (also posting read) */
                WARN_ON(I915_READ_NOTRACE(GEN6_PMIMR) & ~GEN6_PM_RPS_EVENTS);
                /* TODO: if queue_work is slow, move it out of the spinlock */
                queue_work(dev_priv->wq, &dev_priv->rps.work);
+               spin_unlock(&dev_priv->rps.lock);
        }
-       spin_unlock(&dev_priv->rps.lock);
 
-       if (pm_iir & ~GEN6_PM_RPS_EVENTS) {
-               if (pm_iir & PM_VEBOX_USER_INTERRUPT)
-                       notify_ring(dev_priv->dev, &dev_priv->ring[VECS]);
+       if (pm_iir & PM_VEBOX_USER_INTERRUPT)
+               notify_ring(dev_priv->dev, &dev_priv->ring[VECS]);
 
-               if (pm_iir & PM_VEBOX_CS_ERROR_INTERRUPT) {
-                       DRM_ERROR("VEBOX CS error interrupt 0x%08x\n", pm_iir);
-                       i915_handle_error(dev_priv->dev, false);
-               }
+       if (pm_iir & PM_VEBOX_CS_ERROR_INTERRUPT) {
+               DRM_ERROR("VEBOX CS error interrupt 0x%08x\n", pm_iir);
+               i915_handle_error(dev_priv->dev, false);
        }
 }