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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2018-06-28 23:12:03 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2018-06-29 00:55:02 +0300 |
| commit | 74093f3eccac232447ef95536c6a359ee7661650 (patch) | |
| tree | c21d5197ce25fe45e5fb8fed4629bf709cee9221 /drivers/gpu/drm/i915/i915_irq.c | |
| parent | f7dc0157e4b5f23780559c6b71d3f7282f6c7f1b (diff) | |
| download | linux-74093f3eccac232447ef95536c6a359ee7661650.tar.xz | |
drm/i915: Drop posting reads to flush master interrupts
We do not need to do a posting read of our uncached mmio write to
re-enable the master interrupt lines after handling an interrupt, so
don't. This saves us a slow UC read before we can process the interrupt,
most noticeable in execlists where any stalls imposes extra latency on
GPU command execution.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjala <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180628201211.13837-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/i915_irq.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_irq.c | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 4be56aec99b3..02fe0d32382e 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -2183,7 +2183,6 @@ static irqreturn_t valleyview_irq_handler(int irq, void *arg) I915_WRITE(VLV_IER, ier); I915_WRITE(VLV_MASTER_IER, MASTER_INTERRUPT_ENABLE); - POSTING_READ(VLV_MASTER_IER); if (gt_iir) snb_gt_irq_handler(dev_priv, gt_iir); @@ -2268,7 +2267,6 @@ static irqreturn_t cherryview_irq_handler(int irq, void *arg) I915_WRITE(VLV_IER, ier); I915_WRITE(GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL); - POSTING_READ(GEN8_MASTER_IRQ); gen8_gt_irq_handler(dev_priv, master_ctl, gt_iir); @@ -2637,7 +2635,6 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg) /* disable master interrupt before clearing iir */ de_ier = I915_READ(DEIER); I915_WRITE(DEIER, de_ier & ~DE_MASTER_IRQ_CONTROL); - POSTING_READ(DEIER); /* Disable south interrupts. We'll only write to SDEIIR once, so further * interrupts will will be stored on its back queue, and then we'll be @@ -2647,7 +2644,6 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg) if (!HAS_PCH_NOP(dev_priv)) { sde_ier = I915_READ(SDEIER); I915_WRITE(SDEIER, 0); - POSTING_READ(SDEIER); } /* Find, clear, then process each source of interrupt */ @@ -2682,11 +2678,8 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg) } I915_WRITE(DEIER, de_ier); - POSTING_READ(DEIER); - if (!HAS_PCH_NOP(dev_priv)) { + if (!HAS_PCH_NOP(dev_priv)) I915_WRITE(SDEIER, sde_ier); - POSTING_READ(SDEIER); - } /* IRQs are synced during runtime_suspend, we don't require a wakeref */ enable_rpm_wakeref_asserts(dev_priv); |