Re: [PATCH 2/3] ASoC: imx-rpmsg: Support headphone jack detection

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] Headphone jack is initialized after the sound card is fully registered, causing multiple fatal issues including broken jack registration, kernel bugs, and TOCTOU races with userspace.
- [Medium] The patch uses `simple_util_init_jack()` but fails to select its Kconfig dependency, leading to linker errors.
--

commit 23df7e137d741b3d9989cc72e4eb7cee017f18a1
Author: Chancel Liu <chancel.liu@nxp.com>

ASoC: imx-rpmsg: Support headphone jack detection

This commit adds headphone jack detection support for i.MX RPMSG audio cards.
It uses simple_util_init_jack() to register a headphone jack with GPIO-based
insertion detection when the hp-det-gpios property is present.

> diff --git a/sound/soc/fsl/imx-rpmsg.c b/sound/soc/fsl/imx-rpmsg.c
> index 40e0043cfe15e..9c1cf7045381a 100644
> --- a/sound/soc/fsl/imx-rpmsg.c
> +++ b/sound/soc/fsl/imx-rpmsg.c
> @@ -12,6 +12,7 @@
>  #include <sound/control.h>
>  #include <sound/pcm_params.h>
>  #include <sound/soc-dapm.h>
> +#include <sound/simple_card_utils.h>

[Severity: Medium]
Is it possible to hit a linker error here if no other driver selects the
simple card utilities?

This patch uses simple_util_init_jack(), but doesn't appear to update the
Kconfig entry for SND_SOC_IMX_RPMSG to select SND_SIMPLE_CARD_UTILS. If
this driver is built in a configuration where no other selected options
pull in the simple card utilities, it might result in an undefined
reference error.

[ ... ]

> @@ -282,6 +284,12 @@ static int imx_rpmsg_probe(struct platform_device *pdev)
>  		goto fail;
>  	}
>  
> +	if (of_property_present(np, "hp-det-gpios")) {
> +		ret = simple_util_init_jack(&data->card, &data->hp_jack,
> +					    1, NULL, "Headphone Jack");

[Severity: High]
Does initializing the headphone jack after devm_snd_soc_register_card() cause
issues with probe deferral?

If devm_snd_soc_register_card() defers due to a missing component, it queues
the card onto the unbind_card_list and returns 0. The driver then proceeds to
call simple_util_init_jack().

At this point, the snd_card pointer is NULL, which triggers a
snd_BUG_ON(!card) in snd_device_new() and returns -ENXIO. This return
value aborts the probe and breaks probe deferral completely.

Additionally, if the card registers synchronously, snd_card_register() is
called before the jack is initialized. Any ALSA devices added after
registration remain in the SNDRV_DEV_BUILD state and are not exposed to
userspace.

This order also creates a window where userspace daemons might probe the
sound card before the jack is created.

Could this jack initialization be moved to the card's late_probe callback
instead?

> +		if (ret)
> +			goto fail;
> +	}
>  fail:
>  	pdev->dev.of_node = NULL;
>  	return ret;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260526053815.140008-1-chancel.liu@nxp.com?part=2