Re: [PATCH] drm: Fix a infinite loop condition when order becomes 0

[Matthew Auld <matthew.auld@xxxxxxxxx>]

On 14/03/2022 19:40, Arunpravin wrote:
> handle a situation in the condition order-- == min_order,
> when order = 0, leading to order = -1, it now won't exit
> the loop. To avoid this problem, added a order check in
> the same condition, (i.e) when order is 0, we return
> -ENOSPC
>
> Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam@xxxxxxx>

Hmm, it sounded like we were instead going to go with the round_up(size, 
min_page_size), or check and bail if the size is misaligned, in which 
case we don't need this, AFAICT.

> ---
>   drivers/gpu/drm/drm_buddy.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
> index 72f52f293249..5ab66aaf2bbd 100644
> --- a/drivers/gpu/drm/drm_buddy.c
> +++ b/drivers/gpu/drm/drm_buddy.c
> @@ -685,7 +685,7 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm,
>   			if (!IS_ERR(block))
>   				break;
>   
> -			if (order-- == min_order) {
> +			if (!order || order-- == min_order) {
>   				err = -ENOSPC;
>   				goto err_free;
>   			}