From: Paulo Zanoni Date: Tue, 6 Aug 2013 21:57:14 +0000 (-0300) Subject: drm/i915: don't update GEN6_PMIMR when it's not needed X-Git-Tag: next-20130822~66^2~7 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=80998ddec1606fc8e57decca9ae49bf061044d07;p=karo-tx-linux.git drm/i915: don't update GEN6_PMIMR when it's not needed I did some brief tests and the "new_val = pmimr" condition usually happens a few times after exiting games. Note: This is also prep work to track the GEN6_PMIMR register state in dev_priv->pm_imr. This happens in the next patch. Signed-off-by: Paulo Zanoni Reviewed-by: Rodrigo Vivi [danvet: Add note to explain why we want this, as per the discussion between Chris and Paulo.] Signed-off-by: Daniel Vetter --- 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)