EDP_PSR2_CTL
I915_WRITE(EDP_PSR2_CTL, val);
WARN_ON(I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE);
I915_WRITE(EDP_PSR2_CTL,
I915_READ(EDP_PSR2_CTL) &
WARN_ON(I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE);
val = I915_READ(EDP_PSR2_CTL);
I915_WRITE(EDP_PSR2_CTL, val & ~EDP_PSR2_ENABLE);