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

From: Eric Dumazet
Date: Fri Jan 12 2018 - 16:22:07 EST


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.