Re: [PATCH v3] char: nvram: Remove unused nvram_mutex to fix -Wunused-variable warning

Ritesh Harjani
2026-03-30T06:49:56Z

Venkat Rao Bagalkote <venkat88@linux.ibm.com> writes:

> drivers/char/nvram.c defines a static mutex 'nvram_mutex' which is never
> used. This results in a compiler warning on linux-next builds:
>
> warning: 'nvram_mutex' defined but not used [-Wunused-variable]
>
> Remove the unused definition to avoid the warning.
>

That is not the only reason for removing the nvram_mutex. I think we
discussed in detail, why we think this can be removed here [1].
We should add those details in commit msg too.

> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
> Signed-off-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
> ---
> v3:
> - Removed global nvram_mutex entirely

We only removed the mutex definition and not the usage right. This does
not look correct. Maybe you can check sashiko review comments for
details -

https://sashiko.dev/#/patchset/20260330062201.2581-1-venkat88%40linux.ibm.com

-ritesh

>
> drivers/char/nvram.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
> index 9eff426a9286..9ab2744cd375 100644
> --- a/drivers/char/nvram.c
> +++ b/drivers/char/nvram.c
> @@ -53,7 +53,6 @@
> #include <asm/nvram.h>
> #endif
>
> -static DEFINE_MUTEX(nvram_mutex);
> static DEFINE_SPINLOCK(nvram_state_lock);
> static int nvram_open_cnt; /* #times opened */
> static int nvram_open_mode; /* special open modes */
> --
> 2.45.2