drm/i915/tv: Sleep before checking for state changes.

ickle · ickle · commit 29e1316ab129 · 2010-09-23T11:05:44.000+01:00
We need to wait for the PLLs to settle prior to detecting the state
changes. The BIOS writers guide suggests waiting for the next vblank.

Reported-by: Carlos R. Mafra &lt;crmafra2@gmail.com&gt;
Signed-off-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
@@ -1271,8 +1271,12 @@ intel_tv_detect_type (struct intel_tv *intel_tv)
 	I915_WRITE(TV_DAC, tv_dac);
 	POSTING_READ(TV_DAC);
 
+	intel_wait_for_vblank(intel_tv->base.base.dev,
+			      to_intel_crtc(intel_tv->base.base.crtc)->pipe);
+
 	type = -1;
 	if (wait_for((tv_dac = I915_READ(TV_DAC)) & TVDAC_STATE_CHG, 20) == 0) {
+		DRM_DEBUG_KMS("TV detected: %x, %x\n", tv_ctl, tv_dac);
 		/*
 		 *  A B C
 		 *  0 1 1 Composite
@@ -1289,8 +1293,7 @@ intel_tv_detect_type (struct intel_tv *intel_tv)
 			DRM_DEBUG_KMS("Detected Component TV connection\n");
 			type = DRM_MODE_CONNECTOR_Component;
 		} else {
-			DRM_DEBUG_KMS("Unrecognised TV connection: %x\n",
-				      tv_dac);
+			DRM_DEBUG_KMS("Unrecognised TV connection\n");
 		}
 	}
 
