linux-kernel - Re: [PATCH v2 2/2] ASoC: cs42l51: Correct PGA Volume minimum value

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Date:   Mon, 28 Nov 2022 12:14:43 +0100
From:   Guillermo Rodriguez Garcia <guille.rodriguez@...il.com>
To:     Charles Keepax <ckeepax@...nsource.cirrus.com>
Cc:     broonie@...nel.org, lgirdwood@...il.com,
        alsa-devel@...a-project.org, patches@...nsource.cirrus.com,
        james.schulman@...rus.com, david.rhodes@...rus.com,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] ASoC: cs42l51: Correct PGA Volume minimum value

El lun, 28 nov 2022 a las 10:48, Charles Keepax
(<ckeepax@...nsource.cirrus.com>) escribió:
>
> On Sat, Nov 26, 2022 at 12:15:10PM +0100, Guillermo Rodriguez Garcia wrote:
> > El vie, 25 nov 2022 a las 17:37, Charles Keepax
> > (<ckeepax@...nsource.cirrus.com>) escribió:
> > >
> > > The table in the datasheet actually shows the volume values in the wrong
> > > order, with the two -3dB values being reversed. This appears to have
> > > caused the lower of the two values to be used in the driver when the
> > > higher should have been, correct this mixup.
> > >
> > > Signed-off-by: Charles Keepax <ckeepax@...nsource.cirrus.com>
> > > ---
> > >
> > > No changes since v1.
> > >
> > >  sound/soc/codecs/cs42l51.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/sound/soc/codecs/cs42l51.c b/sound/soc/codecs/cs42l51.c
> > > index 51721edd8f53c..e88d9ff95cdfc 100644
> > > --- a/sound/soc/codecs/cs42l51.c
> > > +++ b/sound/soc/codecs/cs42l51.c
> > > @@ -143,7 +143,7 @@ static const struct snd_kcontrol_new cs42l51_snd_controls[] = {
> > >                         0, 0xA0, 96, adc_att_tlv),
> > >         SOC_DOUBLE_R_SX_TLV("PGA Volume",
> > >                         CS42L51_ALC_PGA_CTL, CS42L51_ALC_PGB_CTL,
> > > -                       0, 0x19, 30, pga_tlv),
> > > +                       0, 0x1A, 30, pga_tlv),
> >
> > The original patch where this control was added [1] already used 0x1A,
> > however this was later changed to 0x19 in [2]. Your patch now reverts
> > that change. Does this mean [2] was incorrect? If that is the case,
> > shouldn't the commit message for this patch mention that it fixes [2]
> > ?
> >
> >  [1]: https://lore.kernel.org/all/20200918134317.22574-1-guille.rodriguez@gmail.com/
> >  [2]: https://lore.kernel.org/all/20220602162119.3393857-7-ckeepax@opensource.cirrus.com/
> >
>
> Hmm... good digging, I didn't realise it was me who broke that.
> Apologies in that chain I went around and checked a bunch of SX
> controls to make sure they matched the datasheets, but it seems
> I got a bit confused by the weird ordering of the values in the
> datasheet. Since you have hardware would you be able to check,
> before we merge this revert? A simple check that writing 0 to the
> control sets the register value to 0x1A and writing 30 sets the
> register to 0x18 would suffice.

Just checked. The values are correct after applying the patch:

$ amixer cset name='PGA Volume' '0','0'
$ i2cget -y -f  2 0x4A 0x0A
0x1a
$ i2cget -y -f  2 0x4A 0x0B
0x1a
$ amixer cset name='PGA Volume' '30','30'
$ i2cget -y -f  2 0x4A 0x0A
0x18
$ i2cget -y -f  2 0x4A 0x0B
0x18

BR,

Guillermo Rodriguez Garcia
guille.rodriguez@...il.com