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| author | Daniel Vetter | 2012-11-30 11:24:50 +0100 |
|---|---|---|
| committer | Daniel Vetter | 2012-11-30 19:06:33 +0100 |
| commit | acd15b6cc20f85bcef9e08b6ed4f142c34791c32 (patch) | |
| tree | fe310c1485fbf25a5c36853817e50bee94411edb /drivers/gpu/drm | |
| parent | i915: convert struct spinlock to spinlock_t (diff) | |
| download | kernel-qcow2-linux-acd15b6cc20f85bcef9e08b6ed4f142c34791c32.tar.gz kernel-qcow2-linux-acd15b6cc20f85bcef9e08b6ed4f142c34791c32.tar.xz kernel-qcow2-linux-acd15b6cc20f85bcef9e08b6ed4f142c34791c32.zip | |
drm/i915: optimize ilk/snb irq handler
We only need to read/write the south interrupt register if the
corresponding bit is set in the north master interrupt register.
Noticed while reading our interrupt handling code.
Same optimization has already been applied on ivb in
commit 0e43406bcc1868a316eea6012a0a09d992c53521
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed May 9 21:45:44 2012 +0100
drm/i915: Simplify interrupt processing for IvyBridge
We can take advantage that the PCH_IIR is a subordinate register to
reduce one of the required IIR reads, and that we only need to clear
interrupts handled to reduce the writes. And by simply tidying the code
we can reduce the line count and hopefully make it more readable.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_irq.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 6cd3dc94b472..26753ee6571d 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -758,7 +758,7 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg) struct drm_device *dev = (struct drm_device *) arg; drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private; int ret = IRQ_NONE; - u32 de_iir, gt_iir, de_ier, pch_iir, pm_iir; + u32 de_iir, gt_iir, de_ier, pm_iir; atomic_inc(&dev_priv->irq_received); @@ -769,11 +769,9 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg) de_iir = I915_READ(DEIIR); gt_iir = I915_READ(GTIIR); - pch_iir = I915_READ(SDEIIR); pm_iir = I915_READ(GEN6_PMIIR); - if (de_iir == 0 && gt_iir == 0 && pch_iir == 0 && - (!IS_GEN6(dev) || pm_iir == 0)) + if (de_iir == 0 && gt_iir == 0 && (!IS_GEN6(dev) || pm_iir == 0)) goto done; ret = IRQ_HANDLED; @@ -804,10 +802,15 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg) /* check event from PCH */ if (de_iir & DE_PCH_EVENT) { + u32 pch_iir = I915_READ(SDEIIR); + if (HAS_PCH_CPT(dev)) cpt_irq_handler(dev, pch_iir); else ibx_irq_handler(dev, pch_iir); + + /* should clear PCH hotplug event before clear CPU irq */ + I915_WRITE(SDEIIR, pch_iir); } if (IS_GEN5(dev) && de_iir & DE_PCU_EVENT) @@ -816,8 +819,6 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg) if (IS_GEN6(dev) && pm_iir & GEN6_PM_DEFERRED_EVENTS) gen6_queue_rps_work(dev_priv, pm_iir); - /* should clear PCH hotplug event before clear CPU irq */ - I915_WRITE(SDEIIR, pch_iir); I915_WRITE(GTIIR, gt_iir); I915_WRITE(DEIIR, de_iir); I915_WRITE(GEN6_PMIIR, pm_iir); |