netdev - Re: [PATCH 7/7] ixgbevf: eliminate duplicate barriers on weakly-ordered archs

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Message-ID: <12150aa0-77ba-878e-31f4-d4f8d6a28ccb@codeaurora.org>
Date:   Wed, 14 Mar 2018 00:08:51 -0500
From:   Timur Tabi <timur@...eaurora.org>
To:     Sinan Kaya <okaya@...eaurora.org>, netdev@...r.kernel.org,
        sulrich@...eaurora.org
Cc:     linux-arm-msm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
        intel-wired-lan@...ts.osuosl.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 7/7] ixgbevf: eliminate duplicate barriers on
 weakly-ordered archs

On 3/13/18 10:20 PM, Sinan Kaya wrote:
> +/* Assumes caller has executed a write barrier to order memory and device
> + * requests.
> + */
>   static inline void ixgbevf_write_tail(struct ixgbevf_ring *ring, u32 value)
>   {
> -	writel(value, ring->tail);
> +	writel_relaxed(value, ring->tail);
>   }

Why not put the wmb() in this function, or just get rid of the wmb() in 
the rest of the file and keep this as writel?  That way, you can avoid 
the comment and the risk that comes with it.

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