Re: [PATCH] firmware: exynos-acpm: fix PMIC returned errno

[Krzysztof Kozlowski <krzk@kernel.org>]

On 21/08/2025 15:28, Tudor Ambarus wrote:
> ACPM PMIC command handlers returned a u8 value when they should
> have returned either zero or negative error codes.
> Translate the APM PMIC errno to linux errno.
> 
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/linux-input/aElHlTApXj-W_o1r@stanley.mountain/
> Fixes: a88927b534ba ("firmware: add Exynos ACPM protocol driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
> ---
>  drivers/firmware/samsung/exynos-acpm-pmic.c | 36 +++++++++++++++++++++++++----
>  1 file changed, 31 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/firmware/samsung/exynos-acpm-pmic.c b/drivers/firmware/samsung/exynos-acpm-pmic.c
> index 39b33a356ebd240506b6390163229a70a2d1fe68..a355ee194027c09431f275f0fd296f45652af536 100644
> --- a/drivers/firmware/samsung/exynos-acpm-pmic.c
> +++ b/drivers/firmware/samsung/exynos-acpm-pmic.c
> @@ -5,6 +5,7 @@
>   * Copyright 2024 Linaro Ltd.
>   */
>  #include <linux/bitfield.h>
> +#include <linux/errno.h>
>  #include <linux/firmware/samsung/exynos-acpm-protocol.h>
>  #include <linux/ktime.h>
>  #include <linux/types.h>
> @@ -33,6 +34,26 @@ enum exynos_acpm_pmic_func {
>  	ACPM_PMIC_BULK_WRITE,
>  };
>  
> +enum acpm_pmic_error_codes {

This enum is not used. Size is not needed and you can just use
designated initializers in the array.

> +	ACPM_PMIC_SUCCESS = 0,
> +	ACPM_PMIC_ERR_READ = 1,
> +	ACPM_PMIC_ERR_WRITE = 2,
> +	ACPM_PMIC_ERR_MAX
> +};
> +
> +static int acpm_pmic_linux_errmap[ACPM_PMIC_ERR_MAX] = {

const

> +	0, /* ACPM_PMIC_SUCCESS */
> +	-EACCES, /* Read register can't be accessed or issues to access it. */
> +	-EACCES, /* Write register can't be accessed or issues to access it. */
> +};
> +
> +static inline int acpm_pmic_to_linux_errno(int errno)

Drop inline

s/int errno/int err/
(or code?)

errno is just too similar to Linux errno.


> +{
> +	if (errno >= ACPM_PMIC_SUCCESS && errno < ACPM_PMIC_ERR_MAX)
> +		return acpm_pmic_linux_errmap[errno];
> +	return -EIO;
> +}



Best regards,
Krzysztof