[alsa-devel] [PATCH] ALSA: hda: delay EAPD de-assert for alex system

[Takashi Iwai]

At Fri, 20 May 2011 16:12:51 -0700,
Todd Broch wrote:
> 
> With power savings (CONFIG_SND_HDA_POWER_SAVE) enabled the EAPD GPIO
> de-asserts prior to proper biasing of the speaker inputs into the
> external amplifier causing a 'pop'.  Delaying EAPD by 25ms provides
> necessary setup time to avoid the pop.
> 
> Signed-off-by: Todd Broch <tbroch at chromium.org>

Could you test the latest sound git tree (topic/hda or master branch)
if not done yet?
There was a similar fix (adding some delay in power-up/down path),


thanks,

Takashi


> ---
>  sound/pci/hda/patch_realtek.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
> index c82979a..5b70dc1 100644
> --- a/sound/pci/hda/patch_realtek.c
> +++ b/sound/pci/hda/patch_realtek.c
> @@ -1262,6 +1262,11 @@ static void alc_auto_init_amp(struct hda_codec *codec, int type)
>  		case 0x10ec0269:
>  		case 0x10ec0270:
>  		case 0x10ec0272:
> +			/* delay de-assert of eapd to allow biasing of amp
> +			   inputs to settle avoiding an audible 'pop'
> +			 */
> +			if (codec->subsystem_id == 0x144dc0a7)
> +				msleep(25);
>  		case 0x10ec0660:
>  		case 0x10ec0662:
>  		case 0x10ec0663:
> -- 
> 1.7.3.1
>