Re: [PATCH v2] drm/radeon: silence GCC warning on 32 bit

["Christian König" <christian.koenig@amd.com>]

Am 04.03.2014 10:34, schrieb Paul Bolle:
> Building radeon_ttm.o on 32 bit x86 triggers a warning:
>      In file included from include/asm-generic/bug.h:13:0,
>                       from [...]/arch/x86/include/asm/bug.h:38,
>                       from include/linux/bug.h:4,
>                       from include/drm/drm_mm.h:39,
>                       from include/drm/drm_vma_manager.h:26,
>                       from include/drm/ttm/ttm_bo_api.h:35,
>                       from drivers/gpu/drm/radeon/radeon_ttm.c:32:
>      drivers/gpu/drm/radeon/radeon_ttm.c: In function 'radeon_ttm_gtt_read':
>      include/linux/kernel.h:712:17: warning: comparison of distinct pointer types lacks a cast [enabled by default]
>        (void) (&_min1 == &_min2);  \
>                       ^
>      drivers/gpu/drm/radeon/radeon_ttm.c:938:22: note: in expansion of macro 'min'
>         ssize_t cur_size = min(size, PAGE_SIZE - off);
>                            ^
>
> Silence this warning by using min_t(). Since cur_size will never be
> negative and its upper bound is PAGE_SIZE, we can change its type to
> size_t and use min_t(size_t, [...]) here.
>
> Signed-off-by: Paul Bolle <pebolle@tiscali.nl>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
> v2: use min_t() as Ilia suggested, and convert cur_size to size_t, as
> Thierry suggested.
>
> Still compile tested only (on 32 and 64 bit x86).
>
>   drivers/gpu/drm/radeon/radeon_ttm.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
> index 77f5b0c..1ce6ba6 100644
> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
> @@ -935,7 +935,7 @@ static ssize_t radeon_ttm_gtt_read(struct file *f, char __user *buf,
>   	while (size) {
>   		loff_t p = *pos / PAGE_SIZE;
>   		unsigned off = *pos & ~PAGE_MASK;
> -		ssize_t cur_size = min(size, PAGE_SIZE - off);
> +		size_t cur_size = min_t(size_t, size, PAGE_SIZE - off);
>   		struct page *page;
>   		void *ptr;
>