Re: [PATCH] drm/panthor: Fix clang -Wunused-but-set-variable in tick_ctx_apply()

From: Justin Stitt <justinstitt@google.com>
To: Nathan Chancellor <nathan@kernel.org>
Cc: boris.brezillon@collabora.com, steven.price@arm.com,
	liviu.dudau@arm.com,  maarten.lankhorst@linux.intel.com,
	mripard@kernel.org, tzimmermann@suse.de,
	 ndesaulniers@google.com, morbo@google.com, heiko@sntech.de,
	 dri-devel@lists.freedesktop.org, llvm@lists.linux.dev,
	 patches@lists.linux.dev
Subject: Re: [PATCH] drm/panthor: Fix clang -Wunused-but-set-variable in tick_ctx_apply()
Date: Thu, 28 Mar 2024 14:59:15 -0700	[thread overview]
Message-ID: <CAFhGd8qJQw9TFPzM5VqwPAdvFCfYRW6TMFYZcOOPWW74qvNz6Q@mail.gmail.com> (raw)
In-Reply-To: <20240328-panthor-drop-csg_mod_mask-v1-1-5a80be3df581@kernel.org>

On Thu, Mar 28, 2024 at 9:22 AM Nathan Chancellor <nathan@kernel.org> wrote:
>
> Clang warns (or errors with CONFIG_WERROR):
>
>   drivers/gpu/drm/panthor/panthor_sched.c:2048:6: error: variable 'csg_mod_mask' set but not used [-Werror,-Wunused-but-set-variable]
>    2048 |         u32 csg_mod_mask = 0, free_csg_slots = 0;
>         |             ^
>   1 error generated.
>
> The variable is an artifact left over from refactoring that occurred
> during the development of the initial series for this driver. Remove it
> to resolve the warning.

Yep, makes sense.

>
> Fixes: de8548813824 ("drm/panthor: Add the scheduler logical block")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
>  drivers/gpu/drm/panthor/panthor_sched.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
> index 5f7803b6fc48..e5a710f190d2 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.c
> +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> @@ -2045,7 +2045,7 @@ tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *c
>         struct panthor_device *ptdev = sched->ptdev;
>         struct panthor_csg_slot *csg_slot;
>         int prio, new_csg_prio = MAX_CSG_PRIO, i;
> -       u32 csg_mod_mask = 0, free_csg_slots = 0;
> +       u32 free_csg_slots = 0;
>         struct panthor_csg_slots_upd_ctx upd_ctx;
>         int ret;
>
> @@ -2139,7 +2139,6 @@ tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *c
>
>                         csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
>                         csg_slot = &sched->csg_slots[csg_id];
> -                       csg_mod_mask |= BIT(csg_id);
>                         group_bind_locked(group, csg_id);
>                         csg_slot_prog_locked(ptdev, csg_id, new_csg_prio--);
>                         csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
>
> ---
> base-commit: d180649238f04183950d9c8a7d8a2c2f1788a89c
> change-id: 20240328-panthor-drop-csg_mod_mask-b4bbe317d690
>
> Best regards,
> --
> Nathan Chancellor <nathan@kernel.org>
>