> -----Original Message----- > From: Jani Nikula [mailto:jani.nikula@xxxxxxxxxxxxxxx] > Sent: Friday, November 11, 2016 4:41 PM > To: Yang, Libin <libin.yang@xxxxxxxxx>; intel-gfx@xxxxxxxxxxxxxxxxxxxxx; > ville.syrjala@xxxxxxxxxxxxxxx; Vetter, Daniel <daniel.vetter@xxxxxxxxx>; > tiwai@xxxxxxx > Subject: RE: [PATCH v2] drm/i915/audio: fix hdmi audio noise issue > > On Fri, 11 Nov 2016, "Yang, Libin" <libin.yang@xxxxxxxxx> wrote: > > Hi Jani, > > > >> -----Original Message----- > >> From: Jani Nikula [mailto:jani.nikula@xxxxxxxxxxxxxxx] > >> Sent: Thursday, November 10, 2016 6:37 PM > >> To: Yang, Libin <libin.yang@xxxxxxxxx>; > >> intel-gfx@xxxxxxxxxxxxxxxxxxxxx; ville.syrjala@xxxxxxxxxxxxxxx; > >> Vetter, Daniel <daniel.vetter@xxxxxxxxx>; tiwai@xxxxxxx > >> Cc: Yang, Libin <libin.yang@xxxxxxxxx> > >> Subject: Re: [PATCH v2] drm/i915/audio: fix hdmi audio noise issue > >> > >> On Thu, 10 Nov 2016, libin.yang@xxxxxxxxx wrote: > >> > From: Libin Yang <libin.yang@xxxxxxxxx> > >> > > >> > 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@xxxxxxxxx> > >> > --- > >> > drivers/gpu/drm/i915/intel_audio.c | 15 ++++++++++++--- > >> > 1 file changed, 12 insertions(+), 3 deletions(-) > >> > > >> > diff --git a/drivers/gpu/drm/i915/intel_audio.c > >> > b/drivers/gpu/drm/i915/intel_audio.c > >> > index 813fd74..a472d35 100644 > >> > --- a/drivers/gpu/drm/i915/intel_audio.c > >> > +++ b/drivers/gpu/drm/i915/intel_audio.c > >> > @@ -332,6 +332,13 @@ hsw_hdmi_audio_config_update(struct > intel_crtc > >> *intel_crtc, enum port port, > >> > int n; > >> > u32 tmp; > >> > > >> > + /* reset CTS value to 0 */ > >> > + tmp = I915_READ(HSW_AUD_M_CTS_ENABLE(pipe)); > >> > + tmp &= ~AUD_CONFIG_M_MASK; > >> > + tmp &= ~AUD_M_CTS_M_VALUE_INDEX; > >> > + tmp |= AUD_M_CTS_M_PROG_ENABLE; > >> > + I915_WRITE(HSW_AUD_M_CTS_ENABLE(pipe), tmp); > >> > + > >> > tmp = I915_READ(HSW_AUD_CFG(pipe)); > >> > tmp &= ~AUD_CONFIG_N_VALUE_INDEX; > >> > tmp &= ~AUD_CONFIG_PIXEL_CLOCK_HDMI_MASK; > >> > @@ -351,10 +358,12 @@ 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_VALUE_INDEX; > >> > - tmp |= AUD_M_CTS_M_PROG_ENABLE; > >> > + tmp &= ~AUD_M_CTS_M_PROG_ENABLE; > >> > I915_WRITE(HSW_AUD_M_CTS_ENABLE(pipe), tmp); > >> > >> You did not address my review comment on the earlier version: > >> > >> Is it necessary to do the HSW_AUD_M_CTS_ENABLE updates in two places? > >> Why do you both enable and disable AUD_M_CTS_M_PROG_ENABLE bit > here? > > > > Sorry, I missed your comments. > > > > The first doing the HSW_AUD_M_CTS_ENABLE is to reset the M value to 0. > > The second doing the HSW_AUD_M_CTS_ENABLE is to let HW calculate the > M value. > > > > Or we can just try to disable the HSW_AUD_M_CTS_ENABLE bit. What's > your opinion? > > I would have thought just doing the latter would be sufficient. Please test. I have done the test on 32KHz, 44.1KHz, 48KHz, 88KHz, it is OK. Regards, Libin > > BR, > Jani. > > > > > Regards, > > Libin > > > >> > >> BR, > >> Jani. > >> > >> > >> > } > >> > >> -- > >> Jani Nikula, Intel Open Source Technology Center > > -- > Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
