[PATCH] drm/i915: fix Haswell pfit power well check v2

[Jesse Barnes <jbarnes@virtuousgeek.org>]

We can't read the pfit regs if the power well is off, so use the cached
value.

v2: re-add lost comment (Jesse)
    make sure the crtc using the fitter is actually enabled (Jesse)

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_display.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6504337..6be34f2 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5918,7 +5918,7 @@ static void haswell_modeset_global_resources(struct drm_device *dev)
 		 * sequence that's not yet available. Just in case desktop eDP
 		 * on PORT D is possible on haswell, too. */
 		/* Even the eDP panel fitter is outside the always-on well. */
-		if (I915_READ(PF_WIN_SZ(crtc->pipe)))
+		if (crtc->config.pch_pfit.size && crtc->base.enabled)
 			enable = true;
 	}
 
-- 
1.7.10.4