drm/i915/audio: fix hdmi audio noise issue
authorLibin Yang <libin.yang@intel.com>
Fri, 11 Nov 2016 08:46:28 +0000 (16:46 +0800)
committerJani Nikula <jani.nikula@intel.com>
Mon, 5 Dec 2016 09:00:31 +0000 (11:00 +0200)
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
(cherry picked from commit 60abfbb86a8d51576f90c5adcbb4f547a2952782)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
drivers/gpu/drm/i915/intel_audio.c

index 1c509f7..49f1053 100644 (file)
@@ -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);
 }