Subject: Re: [PATCH] net/mlx4_en: ensure rx_desc updating reaches HW before prod db updating

From: Eric Dumazet <[email-masked]>
Date: Fri, 12 Jan 2018 13:21:59 -0800

On Fri, 2018-01-12 at 13:01 -0800, Saeed Mahameed wrote:

> which is better to grasp ?:
> 
> update_doorbell() {
>     dma_wmb();
>     ring->db = prod;
> }

This one is IMO the most secure one (least surprise)

Considering the time it took to discover this bug, I would really play
safe.

But obviously I do not maintain mlx4.