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SubjectRe: [PATCH v5 3/5] bnx2x: Eliminate duplicate barriers on weakly-ordered archs
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From: Sinan Kaya <okaya@codeaurora.org>
Date: Fri, 23 Mar 2018 12:31:12 -0400

> Sorry, you got me confused now.
>
> If you look at the code closer, you'll see this.
>
> wmb();
>
> txdata->tx_db.data.prod += nbd;
> barrier();
>
> DOORBELL(bp, txdata->cid, txdata->tx_db.raw);
>
> and you also asked me to rename DOORBELL to DOORBELL_RELAXED() to make
> it obvious that we have a relaxed operator inside the macro.

This still doesn't match the stated pattern.

wmb();
/* no other memory or I/O or IOMEM operation */
writel();

There is a write to a producer index there and then no non-compiler
barrier or any kind before the writel().

So, in fact, it might really need that implicit writel() barrier here!

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