Re: [PATCH] drm/drm_vblank.c: avoid unsigned int to signed int cast

[Sui Jingfeng]

Hi,

On 2023/5/22 19:29, Jani Nikula wrote:
> In general, do not use unsigned types in arithmethic to avoid negative
> values, because most people will be tripped over by integer promotion
> rules, and you'll get negative values anyway.


Here I'm sure about this,

but there are plenty unsigned types arithmetic in the kernel.

take kmalloc_array() function as an example in /tools/virto/linux/kernel.h


static inline void *kmalloc_array(unsigned n, size_t s, gfp_t gfp)
{
    return kmalloc(n * s, gfp);
}


NOTE that *size_t* is an unsigned integral data type.