[alsa-devel] [PATCH] ASoC: codec: hdac_hdmi: fix pin connections at cvt enable

[Kai Vehmanen]

Hi,


On Wed, 12 Jun 2019, Takashi Iwai wrote:

> On Wed, 12 Jun 2019 13:55:09 +0200,
> Kai Vehmanen wrote:
> > +			curr = snd_hdac_codec_read(hdev, port->pin->nid,
> > +						   0, AC_VERB_GET_CONNECT_SEL,
> > +						   0);
> > +			if (curr != cvt_idx) {
> > +				snd_hdac_codec_write(hdev,
> > +						     port->pin->nid, 0,
> > +						     AC_VERB_SET_CONNECT_SEL,
> > +						     cvt_idx);
> > +				dev_dbg(&hdev->dev,
> > +					"%s: %s set connect %d -> %d\n",
> > +					__func__, cvt->name, port->pin->nid,
> > +					cvt_idx);
> 
> You can simply restore all pins without reading.  The read costs much
> more time than writes.

aa, thanks, you are probably right. I actually had just the write in my 
first version of the patch, but I ended up adding the read just be on the 
safe side. But true, write with same connection should not have any 
side-effects. I'll change this in v2.

Br, Kai