Re: [PATCH v2 01/10] ASoC: tegra: Fix kcontrol put callback in ADMAIF

Takashi Iwai
2021-11-03T14:16:28Z

On Wed, 03 Nov 2021 14:52:17 +0100,
Sameer Pujar wrote:
>
> The kcontrol put callback is expected to return 1 when there is change
> in HW or when the update is acknowledged by driver. This would ensure
> that change notifications are sent to subscribed applications. Update
> the ADMAIF driver accordingly
>
> Fixes: f74028e159bb ("ASoC: tegra: Add Tegra210 based ADMAIF driver")
> Suggested-by: Jaroslav Kysela <perex@perex.cz>
> Suggested-by: Mark Brown <broonie@kernel.org>
> Signed-off-by: Sameer Pujar <spujar@nvidia.com>
> ---
> sound/soc/tegra/tegra210_admaif.c | 23 ++++++++++++++++++-----
> 1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/sound/soc/tegra/tegra210_admaif.c b/sound/soc/tegra/tegra210_admaif.c
> index bcccdf3..dc71075 100644
> --- a/sound/soc/tegra/tegra210_admaif.c
> +++ b/sound/soc/tegra/tegra210_admaif.c
> @@ -452,16 +452,29 @@ static int tegra_admaif_put_control(struct snd_kcontrol *kcontrol,
> struct tegra_admaif *admaif = snd_soc_component_get_drvdata(cmpnt);
> int value = ucontrol->value.integer.value[0];
>
> - if (strstr(kcontrol->id.name, "Playback Mono To Stereo"))
> + if (strstr(kcontrol->id.name, "Playback Mono To Stereo")) {
> + if (admaif->mono_to_stereo[ADMAIF_TX_PATH][ec->reg] == value)
> + return 0;
> +
> admaif->mono_to_stereo[ADMAIF_TX_PATH][ec->reg] = value;
> - else if (strstr(kcontrol->id.name, "Capture Mono To Stereo"))
> + } else if (strstr(kcontrol->id.name, "Capture Mono To Stereo")) {
> + if (admaif->mono_to_stereo[ADMAIF_RX_PATH][ec->reg] == value)
> + return 0;
> +
> admaif->mono_to_stereo[ADMAIF_RX_PATH][ec->reg] = value;
> - else if (strstr(kcontrol->id.name, "Playback Stereo To Mono"))
> + } else if (strstr(kcontrol->id.name, "Playback Stereo To Mono")) {
> + if (admaif->stereo_to_mono[ADMAIF_TX_PATH][ec->reg] == value)
> + return 0;
> +
> admaif->stereo_to_mono[ADMAIF_TX_PATH][ec->reg] = value;
> - else if (strstr(kcontrol->id.name, "Capture Stereo To Mono"))
> + } else if (strstr(kcontrol->id.name, "Capture Stereo To Mono")) {
> + if (admaif->stereo_to_mono[ADMAIF_RX_PATH][ec->reg] == value)
> + return 0;
> +
> admaif->stereo_to_mono[ADMAIF_RX_PATH][ec->reg] = value;
> + }
>
> - return 0;
> + return 1;

Hrm, that looks too redundant. The similar checks are seen in the get
part, so we may have a better helper function to reduce the string
checks, something like below.

BTW, independent from this patch set, I noticed that those get/put
callbacks handle the wrong type. For enum ctls, you have to use
ucontrol->value.enumerated.value instead of
ucontrol->value.integer.value. The former is long while the latter is
int, hence they may have different sizes.

Such a bug could be caught if you test once with
CONFIG_SND_CTL_VALIDATION=y. It's recommended to test with that
config once for a new driver code.

So, please submit the fix patch(es) for correcting the ctl value
types, too.

thanks,

Takashi

--- a/sound/soc/tegra/tegra210_admaif.c
+++ b/sound/soc/tegra/tegra210_admaif.c
@@ -424,44 +424,46 @@ static const struct snd_soc_dai_ops tegra_admaif_dai_ops = {
.trigger = tegra_admaif_trigger,
};

-static int tegra_admaif_get_control(struct snd_kcontrol *kcontrol,
- struct snd_ctl_elem_value *ucontrol)
+static unsigned int *tegra_admaif_route_val(struct snd_kcontrol *kcontrol)
{
struct snd_soc_component *cmpnt = snd_soc_kcontrol_component(kcontrol);
struct soc_enum *ec = (struct soc_enum *)kcontrol->private_value;
struct tegra_admaif *admaif = snd_soc_component_get_drvdata(cmpnt);
- long *uctl_val = &ucontrol->value.integer.value[0];

if (strstr(kcontrol->id.name, "Playback Mono To Stereo"))
- *uctl_val = admaif->mono_to_stereo[ADMAIF_TX_PATH][ec->reg];
+ return &admaif->mono_to_stereo[ADMAIF_TX_PATH][ec->reg];
else if (strstr(kcontrol->id.name, "Capture Mono To Stereo"))
- *uctl_val = admaif->mono_to_stereo[ADMAIF_RX_PATH][ec->reg];
+ return &admaif->mono_to_stereo[ADMAIF_RX_PATH][ec->reg];
else if (strstr(kcontrol->id.name, "Playback Stereo To Mono"))
- *uctl_val = admaif->stereo_to_mono[ADMAIF_TX_PATH][ec->reg];
+ return &admaif->stereo_to_mono[ADMAIF_TX_PATH][ec->reg];
else if (strstr(kcontrol->id.name, "Capture Stereo To Mono"))
- *uctl_val = admaif->stereo_to_mono[ADMAIF_RX_PATH][ec->reg];
+ return &admaif->stereo_to_mono[ADMAIF_RX_PATH][ec->reg];
+ return NULL;
+}

+static int tegra_admaif_get_control(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ unsigned int *valp = tegra_admaif_route_val(admaif, kcontrol);
+
+ if (!valp)
+ return -EINVAL;
+ ucontrol->value.integer.value[0] = *valp;
return 0;
}

static int tegra_admaif_put_control(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
- struct snd_soc_component *cmpnt = snd_soc_kcontrol_component(kcontrol);
- struct soc_enum *ec = (struct soc_enum *)kcontrol->private_value;
- struct tegra_admaif *admaif = snd_soc_component_get_drvdata(cmpnt);
+ unsigned int *valp = tegra_admaif_route_val(admaif, kcontrol);
int value = ucontrol->value.integer.value[0];

- if (strstr(kcontrol->id.name, "Playback Mono To Stereo"))
- admaif->mono_to_stereo[ADMAIF_TX_PATH][ec->reg] = value;
- else if (strstr(kcontrol->id.name, "Capture Mono To Stereo"))
- admaif->mono_to_stereo[ADMAIF_RX_PATH][ec->reg] = value;
- else if (strstr(kcontrol->id.name, "Playback Stereo To Mono"))
- admaif->stereo_to_mono[ADMAIF_TX_PATH][ec->reg] = value;
- else if (strstr(kcontrol->id.name, "Capture Stereo To Mono"))
- admaif->stereo_to_mono[ADMAIF_RX_PATH][ec->reg] = value;
-
- return 0;
+ if (!valp)
+ return -EINVAL;
+ if (value == *valp)
+ return 0;
+ *valp = value;
+ return 1;
}

static int tegra_admaif_dai_probe(struct snd_soc_dai *dai)