[alsa-devel] [PATCH 1/1] ALSA: ALC283 codec - Avoid pop noise on headphones during suspend/resume

[Takashi Iwai]

At Mon, 20 Oct 2014 04:25:00 +0800,
Hui Wang wrote:
> 
> On 10/13/2014 06:50 PM, David Henningsson wrote:
> >
> > On 2014-10-09 20:41, Takashi Iwai wrote:
> >> At Thu,  9 Oct 2014 11:04:56 +0000,
> >> Harsha Priya wrote:
> >>> This patch sets the headphones mode to default before suspending
> >>> which helps avoid the pop noise on headphones
> >> The change looks simple, but since it's a mysterious COEF, I'd like to
> >> hear from people testing with other machines with this codec before
> >> applying the patch.
> >>
> >> David, do you know anyone in your team have such a machine to test?
> >
> > Looping Hui here, do you have a machine with ALC283 to test with or 
> > knows who has one?
> One of my colleague performed the test, and seems the patch did work.  
> Below is the feedback from my colleague:
> 
> "I tested the patch on Dell Inspiron 3531 which has ALC283 Codec on it.
>   Without the patch, I can hear a pop noise from the headphone, not very harshly, but I can
>   hear there is a pop sound clearly when suspend or reboot.
>   With the patch, there is still a pop sound with very low volume when
>   suspend, you can notice the sound when listening it carefully.
>   When reboot, there is no pop sound."

Thanks for a quick test!
Now I applied it.  I added Cc to stable as it deserves.


Takashi

> 
> 
> Regards,
> Hui.
> 
> >
> >>
> >>
> >> thanks,
> >>
> >> Takashi
> >>
> >>> Signed-off-by: Harsha Priya <harshapriya.n at intel.com>
> >>>
> >>> diff --git a/sound/pci/hda/patch_realtek.c 
> >>> b/sound/pci/hda/patch_realtek.c
> >>> index 69d1236..e839e7a 100644
> >>> --- a/sound/pci/hda/patch_realtek.c
> >>> +++ b/sound/pci/hda/patch_realtek.c
> >>> @@ -2884,6 +2884,9 @@ static void alc283_shutup(struct hda_codec 
> >>> *codec)
> >>>         alc_write_coef_idx(codec, 0x43, 0x9004);
> >>>   +    /*depop hp during suspend*/
> >>> +    alc_write_coef_idx(codec, 0x06, 0x2100);
> >>> +
> >>>       snd_hda_codec_write(codec, hp_pin, 0,
> >>>                   AC_VERB_SET_AMP_GAIN_MUTE, AMP_OUT_MUTE);
> >>>   --
> >>> 1.9.1
> >>>
> >
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> >
>