Re: [PATCH][next] net: hinic: fix comparison of a uint16_t type with -1

[Aviad Krawczyk]

On 8/23/2017 6:39 PM, Colin King wrote:
> From: Colin Ian King <colin.k...@canonical.com>
> 
> The comparison of hw_ioctxt.rx_buf_sz_idx == -1 is always false because
> rx_buf_sz_idx is a uint16_t. Fix this by explicitly casting -1 to uint16_t.
> 
> Detected by CoverityScan, CID#1454559 ("Operands don't affect result")
> 
> Signed-off-by: Colin Ian King <colin.k...@canonical.com>
> ---
>  drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c 
> b/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c
> index 09dec6de8dd5..71e26070fb7f 100644
> --- a/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c
> +++ b/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c
> @@ -352,7 +352,7 @@ static int set_hw_ioctxt(struct hinic_hwdev *hwdev, 
> unsigned int rq_depth,
>               }
>       }
>  
> -     if (hw_ioctxt.rx_buf_sz_idx == -1)
> +     if (hw_ioctxt.rx_buf_sz_idx == (uint16_t)-1)
>               return -EINVAL;
>  
>       hw_ioctxt.sq_depth  = ilog2(sq_depth);
> 

Many thanks, Colin.
I prefer to avoid casting when possible, what do you think about replacing the 
condition by:

if (rx_buf_sz_table[i].sz != HINIC_RX_BUF_SZ)
        return -EINVAL;