Re: [PATCH v6 9/9] rtc: abx80x: add support for ABX81X

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The `regmap_bulk_read` return value check in `abx80x_read_alarm` causes the function to unconditionally fail with `-EIO` on success.
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commit 7f9a5b9080b676338469e285a0ce05b36660c82c
Author: Antoni Pokusinski <apokusinski01@gmail.com>

rtc: abx80x: add support for ABX81X

This patch adds support for the Abracon ABX81X family of RTCs, which feature
a SPI interface. It updates the Kconfig to support both I2C and SPI, and adds
the necessary SPI device IDs, device tree bindings, and probe functions.

> diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
> index c90407a023fe8..c3bf6f0ae48b9 100644
> --- a/drivers/rtc/rtc-abx80x.c
> +++ b/drivers/rtc/rtc-abx80x.c
> @@ -1,7 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  /*
> - * A driver for the I2C members of the Abracon AB x8xx RTC family,
> - * and compatible: AB 1805 and AB 0805
> + * A driver for the I2C and SPI members of the Abracon AB x8xx RTC family,
> + * and compatible: AB 1805, AB 0805, AB 1815 and AB 0815
>   *
>   * Copyright 2014-2015 Macq S.A.
>   *

[Severity: High]
Will the regmap_bulk_read return value check in abx80x_read_alarm() cause the
function to unconditionally fail?

drivers/rtc/rtc-abx80x.c:abx80x_read_alarm() {
...
	err = regmap_bulk_read(priv->regmap, ABX8XX_REG_ASC, buf, sizeof(buf));
	if (err)
		return err;
	if (err < ARRAY_SIZE(buf))
		return -EIO;
...
}

When the RTC core calls abx80x_read_alarm(), regmap_bulk_read() will return 0
on a successful read. The subsequent check evaluates
if (err < ARRAY_SIZE(buf)), which is 0 < 7. This evaluates to true, resulting
in an unconditional return of -EIO and breaking the alarm read functionality
for any unprivileged userspace application reading the RTC alarm.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260907203216.53192-1-apokusinski01@gmail.com?part=9