Re: [PATCH v9 5/5] iio: adc: versal-sysmon: add oversampling support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Software cache for oversampling ratios is unconditionally initialized to 1, potentially causing desynchronization with the actual hardware configuration.
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commit 81ca0dc5aa386dec0337a8e068370935d45ea78e
Author: Salih Erim <salih.erim@amd.com>

iio: adc: versal-sysmon: add oversampling support

This commit adds support for reading and writing the oversampling ratio
through the IIO oversampling_ratio attribute. The hardware supports averaging
2, 4, 8, or 16 samples, plus a ratio of 1 for no averaging.

> diff --git a/drivers/iio/adc/versal-sysmon-core.c b/drivers/iio/adc/versal-sysmon-core.c
> index 19a8edd89198c..16f474c1bffae 100644
> --- a/drivers/iio/adc/versal-sysmon-core.c
> +++ b/drivers/iio/adc/versal-sysmon-core.c
[ ... ]
> @@ -832,6 +981,8 @@ int devm_versal_sysmon_core_probe(struct device *dev, struct regmap *regmap)
>  
>  	sysmon = iio_priv(indio_dev);
>  	sysmon->regmap = regmap;
> +	sysmon->temp_oversampling = 1;
> +	sysmon->supply_oversampling = 1;

[Severity: Medium]
Could this software cache initialization become desynchronized with the actual
hardware configuration?

The oversampling variables are initialized to 1 unconditionally, without
reading the SYSMON_CONFIG hardware register or actively writing this default
value down to the hardware.

If the bootloader or a previous kernel instance (such as through kexec) 
configured an oversampling ratio other than 1, will the hardware continue 
averaging samples while userspace incorrectly reads '1' from the IIO 
oversampling ratio attribute?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260617180147.3370346-1-salih.erim@amd.com?part=5