Re: [PATCH v1 1/1] drm/mm: Mark drm_mm_interval_tree*() functions with __maybe_unused

[Jani Nikula]

On Fri, 30 Aug 2024, Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote:
> On Thu, 29 Aug 2024, Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>> The INTERVAL_TREE_DEFINE() uncoditionally provides a bunch of helper
>> functions which in some cases may be not used. This, in particular,
>> prevents kernel builds with `make W=1` and CONFIG_WERROR=y:
>>
>> .../drm/drm_mm.c:152:1: error: unused function 'drm_mm_interval_tree_insert' [-Werror,-Wunused-function]
>>   152 | INTERVAL_TREE_DEFINE(struct drm_mm_node, rb,
>>       | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>   153 |                      u64, __subtree_last,
>>       |                      ~~~~~~~~~~~~~~~~~~~~
>>   154 |                      START, LAST, static inline, drm_mm_interval_tree)
>>       |                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Fix this by marking drm_mm_interval_tree*() functions with __maybe_unused.
>>
>> Fixes: 202b52b7fbf7 ("drm: Track drm_mm nodes with an interval tree")
>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
>
> As discussed in [1], the key combo is W=1 and Clang, which enables
> detection for unused static inlines.
>
> Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>

Pushed to drm-misc-next, thanks for the patch.

BR,
Jani.

>
>
> BR,
> Jani.
>
>
> [1] https://lore.kernel.org/r/20240829155950.1141978-1-andriy.shevchenko@xxxxxxxxxxxxxxx
>
>
>> ---
>>  drivers/gpu/drm/drm_mm.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
>> index 5ace481c1901..1ed68d3cd80b 100644
>> --- a/drivers/gpu/drm/drm_mm.c
>> +++ b/drivers/gpu/drm/drm_mm.c
>> @@ -151,7 +151,7 @@ static void show_leaks(struct drm_mm *mm) { }
>>  
>>  INTERVAL_TREE_DEFINE(struct drm_mm_node, rb,
>>  		     u64, __subtree_last,
>> -		     START, LAST, static inline, drm_mm_interval_tree)
>> +		     START, LAST, static inline __maybe_unused, drm_mm_interval_tree)
>>  
>>  struct drm_mm_node *
>>  __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last)

-- 
Jani Nikula, Intel