drm/i915: Set correct TV detection voltage level override values
We detect TV connect status by setting DAC voltage level override
values as 0.7 voltage for DAC_A/B/C. The corresponding 2-bits shold be 0x2,
In order correctly to set last bit as 0, at first we must clean it.
It fixed freedesktop.org bug #21204
Signed-off-by: Ma Ling <ling.ma@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
index d2c3298..c7d9ef0 100644
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -1392,6 +1392,9 @@
tv_ctl &= ~TV_TEST_MODE_MASK;
tv_ctl |= TV_TEST_MODE_MONITOR_DETECT;
tv_dac &= ~TVDAC_SENSE_MASK;
+ tv_dac &= ~DAC_A_MASK;
+ tv_dac &= ~DAC_B_MASK;
+ tv_dac &= ~DAC_C_MASK;
tv_dac |= (TVDAC_STATE_CHG_EN |
TVDAC_A_SENSE_CTL |
TVDAC_B_SENSE_CTL |