From 60abfbb86a8d51576f90c5adcbb4f547a2952782 Mon Sep 17 00:00:00 2001 From: Libin Yang Date: Fri, 11 Nov 2016 16:46:28 +0800 Subject: [PATCH] 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 Signed-off-by: Jani Nikula Link: http://patchwork.freedesktop.org/patch/msgid/1478853988-139842-1-git-send-email-libin.yang@intel.com --- drivers/gpu/drm/i915/intel_audio.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c index 1c509f7410f5..49f10538d4aa 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); } -- 2.20.1