SPLL_CTL
pll = I915_READ(SPLL_CTL) & SPLL_PLL_FREQ_MASK;
I915_STATE_WARN(I915_READ(SPLL_CTL) & SPLL_PLL_ENABLE, "SPLL enabled\n");
I915_WRITE(SPLL_CTL, pll->state.hw_state.spll);
POSTING_READ(SPLL_CTL);
val = I915_READ(SPLL_CTL);
I915_WRITE(SPLL_CTL, val & ~SPLL_PLL_ENABLE);
POSTING_READ(SPLL_CTL);
val = I915_READ(SPLL_CTL);