Re: Fwd: [Bug 217440] New: ALC236 audio disappears from HP 15z-fc000 on warm boot

[Takashi Iwai <tiwai@suse.de>]

On Fri, 09 Jun 2023 05:04:29 +0200,
Kailang wrote:
> 
> Hi Takashi,
> 
> ALC236 works normally.
> But codec register can't show it. (it shows "Invalid AFG subtree")
> Could you know why?

It's the call of snd_hda_get_subnodes(), i.e. snd_hdac_get_subnodes(),
which simply reads the raw parameter value (uncached)
AC_PAR_NODE_COUNT:

int snd_hdac_get_sub_nodes(struct hdac_device *codec, hda_nid_t nid,
                           hda_nid_t *start_id)
{
        unsigned int parm;

        parm = snd_hdac_read_parm_uncached(codec, nid, AC_PAR_NODE_COUNT);
        if (parm == -1) {
                *start_id = 0;
                return 0;
        }
        *start_id = (parm >> 16) & 0x7fff;
        return (int)(parm & 0x7fff);
}

So it means the read of this parameter failed.

I suppose this is under the power-save, and it might be some timing
issue?  What if you disable the codec power saving?  The easiest way
would be to pass
  echo 0 > /sys/module/snd_hda_intel/parameters/power_save


thanks,

Takashi

> 
> BR,
> Kailang
> > -----Original Message-----
> > From: Joseph C. Sible <josephcsible@gmail.com>
> > Sent: Thursday, June 8, 2023 10:43 PM
> > To: Kailang <kailang@realtek.com>
> > Cc: Takashi Iwai <tiwai@suse.de>; Bagas Sanjaya <bagasdotme@gmail.com>;
> > regressions@lists.linux.dev; perex@perex.cz; tiwai@suse.com;
> > alsa-devel@alsa-project.org
> > Subject: Re: Fwd: [Bug 217440] New: ALC236 audio disappears from HP
> > 15z-fc000 on warm boot
> > 
> > 
> > External mail.
> > 
> > 
> > 
> > On Thu, Jun 8, 2023 at 2:32 AM Kailang <kailang@realtek.com> wrote:
> > >
> > > Could you use your patch to dump codec info again?
> > > I want to check it will also show "invalid AFG subtree".
> > 
> > Okay, here's the same command's output again, this time from under the
> > kernel with my patch that does fix the problem. It does also show "invalid AFG
> > subtree".
> > 
> > Thanks,
> > 
> > Joseph C. Sible
> > 
> > ------Please consider the environment before printing this e-mail.