So don't write it, otherwise we will trigger unclaimed register
errors.
Testcase: igt/pm_rpm/rte
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
        WARN(I915_READ(PCH_PP_STATUS) & PP_ON, "Panel power on\n");
        WARN(I915_READ(BLC_PWM_CPU_CTL2) & BLM_PWM_ENABLE,
             "CPU PWM1 enabled\n");
-       WARN(I915_READ(HSW_BLC_PWM2_CTL) & BLM_PWM_ENABLE,
-            "CPU PWM2 enabled\n");
+       if (IS_HASWELL(dev))
+               WARN(I915_READ(HSW_BLC_PWM2_CTL) & BLM_PWM_ENABLE,
+                    "CPU PWM2 enabled\n");
        WARN(I915_READ(BLC_PWM_PCH_CTL1) & BLM_PCH_PWM_ENABLE,
             "PCH PWM1 enabled\n");
        WARN(I915_READ(UTIL_PIN_CTL) & UTIL_PIN_ENABLE,