Re: [PATCH 8/9] mlx5: stop warning for 64KB pages

Tariq Toukan
2024-03-28T22:39:29Z

On 28/03/2024 16:30, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> When building with 64KB pages, clang points out that xsk->chunk_size
> can never be PAGE_SIZE:
>
> drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c:19:22: error: result of comparison of constant 65536 with expression of type 'u16' (aka 'unsigned short') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
> if (xsk->chunk_size > PAGE_SIZE ||
> ~~~~~~~~~~~~~~~ ^ ~~~~~~~~~
>
> In older versions of this code, using PAGE_SIZE was the only
> possibility, so this would have never worked on 64KB page kernels,
> but the patch apparently did not address this case completely.
>
> As Maxim Mikityanskiy suggested, 64KB chunks are really not all that
> useful, so just shut up the warning by adding a cast.
>
> Fixes: 282c0c798f8e ("net/mlx5e: Allow XSK frames smaller than a page")
> Link: https://lore.kernel.org/netdev/20211013150232.2942146-1-arnd@kernel.org/
> Link: https://lore.kernel.org/lkml/a7b27541-0ebb-4f2d-bd06-270a4d404613@app.fastmail.com/
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for your patch.

Reviewed-by: Tariq Toukan <tariqt@nvidia.com>