[Intel-gfx] [PATCH 01/12] drm/i915: enable dip before writing data on gen4

[Paulo Zanoni]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

While testing with the intel_infoframes tool on gen4, I see that when
video DIP is disabled, what we write to the DATA memory is not exactly
what we read back later. This should fix some problems that can be
bisected to "drm/i915: fix ILK+ infoframe support". That commit was
setting VIDEO_DIP_CTL to 0 when initializing, which caused the problem.
Fixes fd.o bug 43947.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43947
Cc: stable at kernel.org

Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/intel_hdmi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 7de2d3b..1eef50d 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -136,7 +136,7 @@ static void i9xx_write_infoframe(struct drm_encoder *encoder,
 
 	val &= ~VIDEO_DIP_SELECT_MASK;
 
-	I915_WRITE(VIDEO_DIP_CTL, val | port | flags);
+	I915_WRITE(VIDEO_DIP_CTL, VIDEO_DIP_ENABLE | val | port | flags);
 
 	for (i = 0; i < len; i += 4) {
 		I915_WRITE(VIDEO_DIP_DATA, *data);
-- 
1.7.10