[alsa-devel] [PATCH 2/2] ALSA: hda - get realtime ELD info when codec suspended

[Wang, Xingchao]

> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai at suse.de]
> Sent: Monday, June 24, 2013 7:36 PM
> To: Wang Xingchao
> Cc: alsa-devel at alsa-project.org; Wang, Xingchao
> Subject: Re: [PATCH 2/2] ALSA: hda - get realtime ELD info when codec
> suspended
> 
> At Mon, 24 Jun 2013 07:45:24 -0400,
> Wang Xingchao wrote:
> >
> > when controller/codec in runtime suspended mode, monitor hotplug would
> > not trigger unsolicited event. This patch tries to power up codec and
> > hdmi driver would probe ELD info again.
> 
> I don't know whether this is the wanted behavior.
> The proc file is supposed to read the driver's status, not to trigger anything.
> 

I explained in another mail what the patch fix. In the real case, when HDMI monitor removed,
Eld# still hold monitor information because the codec/controller is in suspend mode atm and has no chance to refresh eld.
Even when controller/codec waken up, it will not refresh eld# as gfx side handled hdmi hotplut when audio driver suspended.
Then user will always see eld valid info but in fact the monitor is removed already, obviously it's a bug.

Thanks
--xingchao

> 
> Takashi
> 
> > Signed-off-by: Wang Xingchao <xingchao.wang at linux.intel.com>
> > ---
> >  sound/pci/hda/hda_eld.c   | 6 ++++++
> >  sound/pci/hda/hda_local.h | 1 +
> >  2 files changed, 7 insertions(+)
> >
> > diff --git a/sound/pci/hda/hda_eld.c b/sound/pci/hda/hda_eld.c index
> > d0d7ac1..914712a 100644
> > --- a/sound/pci/hda/hda_eld.c
> > +++ b/sound/pci/hda/hda_eld.c
> > @@ -482,6 +482,7 @@ static void hdmi_print_eld_info(struct
> snd_info_entry *entry,
> >  				struct snd_info_buffer *buffer)
> >  {
> >  	struct hdmi_eld *eld = entry->private_data;
> > +	struct hda_codec *codec = eld->codec;
> >  	struct parsed_hdmi_eld *e = &eld->info;
> >  	char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
> >  	int i;
> > @@ -500,11 +501,14 @@ static void hdmi_print_eld_info(struct
> snd_info_entry *entry,
> >  		[4 ... 7] = "reserved"
> >  	};
> >
> > +	snd_hda_power_up(codec);
> > +
> >  	mutex_lock(&eld->lock);
> >  	snd_iprintf(buffer, "monitor_present\t\t%d\n", eld->monitor_present);
> >  	snd_iprintf(buffer, "eld_valid\t\t%d\n", eld->eld_valid);
> >  	if (!eld->eld_valid) {
> >  		mutex_unlock(&eld->lock);
> > +		snd_hda_power_down(codec);
> >  		return;
> >  	}
> >  	snd_iprintf(buffer, "monitor_name\t\t%s\n", e->monitor_name); @@
> > -529,6 +533,7 @@ static void hdmi_print_eld_info(struct snd_info_entry
> *entry,
> >  	for (i = 0; i < e->sad_count; i++)
> >  		hdmi_print_sad_info(i, e->sad + i, buffer);
> >  	mutex_unlock(&eld->lock);
> > +	snd_hda_power_down(codec);
> >  }
> >
> >  static void hdmi_write_eld_info(struct snd_info_entry *entry, @@
> > -614,6 +619,7 @@ int snd_hda_eld_proc_new(struct hda_codec *codec,
> struct hdmi_eld *eld,
> >  	entry->c.text.write = hdmi_write_eld_info;
> >  	entry->mode |= S_IWUSR;
> >  	eld->proc_entry = entry;
> > +	eld->codec = codec;
> >
> >  	return 0;
> >  }
> > diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
> > index e0bf753..1aaf8b6 100644
> > --- a/sound/pci/hda/hda_local.h
> > +++ b/sound/pci/hda/hda_local.h
> > @@ -747,6 +747,7 @@ struct hdmi_eld {
> >  #ifdef CONFIG_PROC_FS
> >  	struct snd_info_entry *proc_entry;
> >  #endif
> > +	struct hda_codec *codec;
> >  };
> >
> >  int snd_hdmi_get_eld_size(struct hda_codec *codec, hda_nid_t nid);
> > --
> > 1.8.1.2
> >