Re: [PATCH v1 01/21] hwmon: Fix the type of 'config' in struct hwmon_channel_info to u64

Russell King (Oracle)
2025-01-21T17:05:57Z

On Tue, Jan 21, 2025 at 02:44:59PM +0800, Huisong Li wrote:
> */
> struct hwmon_channel_info {
> enum hwmon_sensor_types type;
> - const u32 *config;
> + const u64 *config;
> };
>
> #define HWMON_CHANNEL_INFO(stype, ...) \
> (&(const struct hwmon_channel_info) { \
> .type = hwmon_##stype, \
> - .config = (const u32 []) { \
> + .config = (const u64 []) { \
> __VA_ARGS__, 0 \
> } \
> })

I'm sorry, but... no. Just no. Have you tried building with only your
first patch?

It will cause the compiler to barf on, e.g. the following:

static u32 marvell_hwmon_chip_config[] = {
...

static const struct hwmon_channel_info marvell_hwmon_chip = {
.type = hwmon_chip,
.config = marvell_hwmon_chip_config,
};

I suggest that you rearrange your series: first, do the conversions
to HWMON_CHANNEL_INFO() in the drivers you have.

At this point, if all the drivers that assign to hw_channel_info.config
have been converted, this patch 1 is then suitable.

If there are still drivers that assign a u32 array to
hw_channel_info.config, then you need to consider how to handle
that without causing regressions. You can't cast it between a u32
array and u64 array to silence the warning, because config[1]
won't point at the next entry.

I think your only option would be to combine the conversion of struct
hwmon_channel_info and the other drivers into a single patch. Slightly
annoying, but without introducing more preprocessor yuckiness, I don't
see another way.

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