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

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 <crmafra2@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
index 49ab11c667bb9bb0e1fdbf33f3295bba183123c0..106560bc84db0292b0cfacb2efb63ef0e8780bac 100644 (file)
--- 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");
                }
        }