drm/i915/audio: fix hdmi audio noise issue
Some monitors will have noise or even no sound after
applying the patch 6014ac12.
In patch 6014ac12, it will reset the cts value to 0 for HDMI.
However, we need to disable Enable CTS or M Prog bit. This is
the initial setting after HW reset.
Fixes: 6014ac122ed0 ("drm/i915/audio: set proper N/M in modeset")
Signed-off-by: Libin Yang <libin.yang@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1478853988-139842-1-git-send-email-libin.yang@intel.com
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index 1c509f741..49f1053 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -351,10 +351,13 @@ hsw_hdmi_audio_config_update(struct intel_crtc *intel_crtc, enum port port,
I915_WRITE(HSW_AUD_CFG(pipe), tmp);
+ /*
+ * Let's disable "Enable CTS or M Prog bit"
+ * and let HW calculate the value
+ */
tmp = I915_READ(HSW_AUD_M_CTS_ENABLE(pipe));
- tmp &= ~AUD_CONFIG_M_MASK;
+ tmp &= ~AUD_M_CTS_M_PROG_ENABLE;
tmp &= ~AUD_M_CTS_M_VALUE_INDEX;
- tmp |= AUD_M_CTS_M_PROG_ENABLE;
I915_WRITE(HSW_AUD_M_CTS_ENABLE(pipe), tmp);
}