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From:   Yu-Hsuan Hsu <yuhsuan@chromium.org>
Date:   Sat, 18 Jul 2020 02:51:08 +0800
Message-ID: <CAGvk5Prz_62Gzu98eZFDotzQOz5tMN72PB4UA9m315-PVfrsNQ@mail.gmail.com>
Subject: Re: [PATCH v2] ASoC: cros_ec_codec: Reset I2S RX when probing
To:     Guenter Roeck <groeck@google.com>
Cc:     Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Tzung-Bi Shih <tzungbi@google.com>,
        Cheng-Yi Chiang <cychiang@chromium.org>,
        Guenter Roeck <groeck@chromium.org>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>,
        Benson Leung <bleung@chromium.org>,
        ALSA development <alsa-devel@alsa-project.org>
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Guenter Roeck <groeck@google.com> =E6=96=BC 2020=E5=B9=B47=E6=9C=8817=E6=97=
=A5 =E9=80=B1=E4=BA=94 =E4=B8=8B=E5=8D=8810:32=E5=AF=AB=E9=81=93=EF=BC=9A
>
> On Thu, Jul 16, 2020 at 10:47 AM Enric Balletbo i Serra
> <enric.balletbo@collabora.com> wrote:
> >
> > Hi,
> >
> > On 16/7/20 19:23, Guenter Roeck wrote:
> > > On Thu, Jul 16, 2020 at 10:09 AM Yu-Hsuan Hsu <yuhsuan@chromium.org> =
wrote:
> > >>
> > >> It is not guaranteed that I2S RX is disabled when the kernel booting=
.
> > >> For example, if the kernel crashes while it is enabled, it will keep
> > >> enabled until the next time EC reboots. Reset I2S RX when probing to
> > >> fix this issue.
> > >>
> > >> Signed-off-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
> > >> ---
> > >>  drivers/platform/chrome/cros_ec_proto.c        | 7 ++++++-
> > >>  include/linux/platform_data/cros_ec_commands.h | 1 +
> > >>  sound/soc/codecs/cros_ec_codec.c               | 9 +++++++++
> > >>  3 files changed, 16 insertions(+), 1 deletion(-)
> > >>
> > >> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platf=
orm/chrome/cros_ec_proto.c
> > >> index 3e745e0fe092c..2c60690d7147c 100644
> > >> --- a/drivers/platform/chrome/cros_ec_proto.c
> > >> +++ b/drivers/platform/chrome/cros_ec_proto.c
> > >> @@ -572,7 +572,12 @@ int cros_ec_cmd_xfer_status(struct cros_ec_devi=
ce *ec_dev,
> > >>                 return -ENOTSUPP;
> > >>         } else if (msg->result !=3D EC_RES_SUCCESS) {
> > >>                 dev_dbg(ec_dev->dev, "Command result (err: %d)\n", m=
sg->result);
> > >> -               return -EPROTO;
> > >> +               switch (msg->result) {
> > >> +               case EC_RES_INVALID_PARAM:
> > >> +                       return -EINVAL;
> > >
> > > As we have learned, this may impact other callers of
> > > cros_ec_cmd_xfer_status() which only accept -EPROTO as error return
> > > value. In addition to that, the code is odd:
> > >
> > >     if (msg->result =3D=3D EC_RES_INVALID_VERSION) {
> > >         ...
> > >     } else if (msg->result !=3D EC_RES_SUCCESS) {
> > >         switch (msg->result) {
> > >         ....
> > >         }
> > >     }
> > >
> >
> > Ack, this is odd.
> >
> > > I really dislike the notion of changing error return values of
> > > cros_ec_cmd_xfer_status() one by one. That can only cause ongoing
> > > trouble with callers expecting specific error return codes (as we hav=
e
> > > already seen).
> > >
> >
> > Hmm, that's a good point. Ok.
> >
> > Let's apply the Guenter's patch that maps the errors *and* fix the call=
ers of
> > cros_ec_cmd_xfer_status which only accept -EPROTO (there are few).
> >
> > Yu-Hsuan, can you take care of this and send a patch series with all th=
e
> > required patches? If not, I can work on this next week.
> >
>
> I can look into it as well. Let me know - I don't want to duplicate work.
>
> Guenter
Hi Guenter,
Really thanks for your assistance! Could you help me on those patches?
Since you wrote that patch, I think it should be the most efficient
way to make them merged.

Thanks,
Yu-Hsuan

>
> > Thanks,
> >   Enric
> >
> > > Guenter
> > >
> > >> +               default:
> > >> +                       return -EPROTO;
> > >> +               }
> > >>         }
> > >>
> > >>         return ret;
> > >> diff --git a/include/linux/platform_data/cros_ec_commands.h b/includ=
e/linux/platform_data/cros_ec_commands.h
> > >> index 69210881ebac8..11ce917ca924c 100644
> > >> --- a/include/linux/platform_data/cros_ec_commands.h
> > >> +++ b/include/linux/platform_data/cros_ec_commands.h
> > >> @@ -4598,6 +4598,7 @@ enum ec_codec_i2s_rx_subcmd {
> > >>         EC_CODEC_I2S_RX_SET_SAMPLE_DEPTH =3D 0x2,
> > >>         EC_CODEC_I2S_RX_SET_DAIFMT =3D 0x3,
> > >>         EC_CODEC_I2S_RX_SET_BCLK =3D 0x4,
> > >> +       EC_CODEC_I2S_RX_RESET =3D 0x5,
> > >>         EC_CODEC_I2S_RX_SUBCMD_COUNT,
> > >>  };
> > >>
> > >> diff --git a/sound/soc/codecs/cros_ec_codec.c b/sound/soc/codecs/cro=
s_ec_codec.c
> > >> index f23956cf4ed84..b5ff30b7f1aa8 100644
> > >> --- a/sound/soc/codecs/cros_ec_codec.c
> > >> +++ b/sound/soc/codecs/cros_ec_codec.c
> > >> @@ -1034,6 +1034,15 @@ static int cros_ec_codec_platform_probe(struc=
t platform_device *pdev)
> > >>         }
> > >>         priv->ec_capabilities =3D r.capabilities;
> > >>
> > >> +       /* Reset EC codec I2S RX. */
> > >> +       p.cmd =3D EC_CODEC_I2S_RX_RESET;
> > >> +       ret =3D send_ec_host_command(priv->ec_device, EC_CMD_EC_CODE=
C_I2S_RX,
> > >> +                                  (uint8_t *)&p, sizeof(p), NULL, 0=
);
> > >> +       if (ret =3D=3D -EINVAL)
> > >> +               dev_info(dev, "Missing reset command. Please update =
your EC firmware.\n");
> > >> +       else if (ret)
> > >> +               dev_err(dev, "failed to EC_CODEC_I2S_RESET: %d\n", r=
et);
> > >> +
> > >>         platform_set_drvdata(pdev, priv);
> > >>
> > >>         ret =3D devm_snd_soc_register_component(dev, &i2s_rx_compone=
nt_driver,
> > >> --
> > >> 2.27.0.389.gc38d7665816-goog
> > >>