Re: [PATCH] ALSA: hda: Use maple tree register cache

Takashi Iwai
2023-06-13T07:36:46Z

On Sun, 11 Jun 2023 09:37:21 +0200,
Takashi Iwai wrote:
>
> On Sat, 10 Jun 2023 16:26:37 +0200,
> Mark Brown wrote:
> >
> > HDA can only support single register read and write operations so does not
> > benefit from block writes. This means it gets no benefit from using the
> > rbtree register cache over the maple tree register cache so convert it to
> > use maple trees instead, it is more modern.
> >
> > Signed-off-by: Mark Brown <broonie@kernel.org>
>
> Thanks, applied to for-next branch.

Now I noticed errors like

snd_hda_codec_realtek hdaudioC0D0: Unable to sync register 0x2f0009. -5

and it turned out that the error comes from this patch.

This is an error from regache_sync_val(), and it indicates that the
synced register is write-only; regcache_maple_sync() tries to sync all
cached values no matter whether it's writable or not, then hitting
this.

I'll submit a fix patch.

thanks,

Takashi