Re: [PATCH v5 6/7] ASoC: qcom: common: add DAI-node TDM slot helpers

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] qcom_snd_apply_dai_tdm_slots() silently swallows validation errors from qcom_snd_normalize_tdm_slots(), hiding device tree misconfigurations.
--

--- Patch [6]: [PATCH v5 6/7] ASoC: qcom: common: add DAI-node TDM slot helpers ---
commit f8d4d2026fa6be0ea3757ca3a1aa7c0d4b41e96e
Author: Prasad Kumpatla <prasad.kumpatla@oss.qualcomm.com>

ASoC: qcom: common: add DAI-node TDM slot helpers

This patch adds common helpers to parse standard dai-tdm-slot-* properties
from the CPU and codec child nodes of a backend DAI link and applies the
result to the active DAIs. It provides configuration parsing, validation,
and an apply helper for callers.

> diff --git a/sound/soc/qcom/common.c b/sound/soc/qcom/common.c
> index e4ff247ea47fd..cacf467bc2a76 100644
> --- a/sound/soc/qcom/common.c
> +++ b/sound/soc/qcom/common.c
[ ... ]
> +static int qcom_snd_normalize_tdm_slots(struct qcom_snd_tdm_slot_cfg *cpu_cfg,
> +					struct qcom_snd_tdm_slot_cfg *codec_cfg)
> +{
> +	unsigned int slots;
> +	unsigned int slot_width;
> +
> +	if (cpu_cfg->slots && codec_cfg->slots && cpu_cfg->slots != codec_cfg->slots)
> +		return -EINVAL;
> +
> +	if (cpu_cfg->slot_width && codec_cfg->slot_width &&
> +	    cpu_cfg->slot_width != codec_cfg->slot_width)
> +		return -EINVAL;
[ ... ]
> +int qcom_snd_apply_dai_tdm_slots(struct snd_soc_pcm_runtime *rtd)
> +{
> +	struct qcom_snd_tdm_slot_cfg cpu_cfg;
> +	struct qcom_snd_tdm_slot_cfg codec_cfg;
> +	int ret;
> +
> +	ret = qcom_snd_get_dai_tdm_slots(rtd, &cpu_cfg, &codec_cfg);
> +	if (ret)
> +		return ret == -EINVAL ? 0 : ret;

[Severity: Medium]
Will this silently swallow validation errors from conflicting device tree
configurations?

While this logic appears intended to ignore -EINVAL when TDM nodes are simply
missing in qcom_snd_parse_dai_tdm_slots(), qcom_snd_normalize_tdm_slots()
also returns -EINVAL when there are contradictory settings (such as conflicting
slot counts or widths between CPU and codec nodes).

If a device tree is provided with contradictory TDM properties, won't this
result in the error being hidden and no TDM configuration being applied,
likely leading to silent audio failures instead of failing probe with an error?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260801054610.4047089-1-prasad.kumpatla@oss.qualcomm.com?part=6