diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_irq.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_irq.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index af5c335a69db..efe3fc671e1e 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -142,14 +142,18 @@ static void snb_update_pm_irq(struct drm_i915_private *dev_priv, uint32_t interrupt_mask, uint32_t enabled_irq_mask) { - uint32_t pmimr = I915_READ(GEN6_PMIMR); - pmimr &= ~interrupt_mask; - pmimr |= (~enabled_irq_mask & interrupt_mask); + uint32_t pmimr, new_val; assert_spin_locked(&dev_priv->irq_lock); - I915_WRITE(GEN6_PMIMR, pmimr); - POSTING_READ(GEN6_PMIMR); + pmimr = new_val = I915_READ(GEN6_PMIMR); + new_val &= ~interrupt_mask; + new_val |= (~enabled_irq_mask & interrupt_mask); + + if (new_val != pmimr) { + I915_WRITE(GEN6_PMIMR, new_val); + POSTING_READ(GEN6_PMIMR); + } } void snb_enable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask) |