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From:   Yu-Hsuan Hsu <yuhsuan@chromium.org>
Date:   Fri, 3 Jul 2020 16:10:39 +0800
Message-ID: <CAGvk5PpSO5yjsvF1jq6v+EdPBvZVeEGgPJJeuixjZJ7MS-DvWg@mail.gmail.com>
Subject: Re: [PATCH v2] ASoC: cros_ec_codec: Log results when EC commands fail
To:     Tzung-Bi Shih <tzungbi@google.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Cheng-Yi Chiang <cychiang@chromium.org>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        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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Tzung-Bi Shih <tzungbi@google.com> =E6=96=BC 2020=E5=B9=B47=E6=9C=883=E6=97=
=A5 =E9=80=B1=E4=BA=94 =E4=B8=8B=E5=8D=883:32=E5=AF=AB=E9=81=93=EF=BC=9A
>
> On Fri, Jul 3, 2020 at 3:19 PM Yu-Hsuan Hsu <yuhsuan@chromium.org> wrote:
> > Log results of failed EC commands to identify a problem more easily.
> >
> > Replace cros_ec_cmd_xfer_status with cros_ec_cmd_xfer because the resul=
t
> > has already been checked in this function. The wrapper is not needed.
>
> Alternatively, you can still use cros_ec_cmd_xfer_status( ).  I guess
> it is okay to have 2 logs for an error.
>
> > diff --git a/sound/soc/codecs/cros_ec_codec.c b/sound/soc/codecs/cros_e=
c_codec.c
> > index 8d45c628e988e..a4ab62f59efa6 100644
> > --- a/sound/soc/codecs/cros_ec_codec.c
> > +++ b/sound/soc/codecs/cros_ec_codec.c
> > @@ -90,10 +90,17 @@ static int send_ec_host_command(struct cros_ec_devi=
ce *ec_dev, uint32_t cmd,
> >         if (outsize)
> >                 memcpy(msg->data, out, outsize);
> >
> > -       ret =3D cros_ec_cmd_xfer_status(ec_dev, msg);
> > +       ret =3D cros_ec_cmd_xfer(ec_dev, msg);
> >         if (ret < 0)
> I am thinking of if it is a better solution to print msg->result here.
The problem is the msg->result is not always meaningful.
In cros_ec_cmd_xfer_status, we know that the msg->result is meaningful
only when ret =3D=3D 0. Therefore, we can not print the msg->result
directly here.

In addition, adding a conditional operator here to check whether ret
is -EPROTO is not a good way, either.
We should consider the situation that cros_ec_cmd_xfer may return
-EPROTO directly.

>
> >                 goto error;
> >
> > +       if (msg->result !=3D EC_RES_SUCCESS) {
> > +               dev_err(ec_dev->dev, "Command %d failed: %d\n", cmd,
> > +                       msg->result);
> > +               ret =3D -EPROTO;
> > +               goto error;
> > +       }
> So that you don't need this block.