From mboxrd@z Thu Jan  1 00:00:00 1970
From: hch@infradead.org (Christoph Hellwig)
Date: Thu, 10 Mar 2016 06:36:50 -0800
Subject: [PATCH] nvme: avoid cqe corruption when update at the same time
 as read
In-Reply-To: <881149974.3314758.1457608128188.JavaMail.zimbra@kalray.eu>
References: <1963234885.1121305.1457109031908.JavaMail.zimbra@kalray.eu>
 <1380738962.1128342.1457162595145.JavaMail.zimbra@kalray.eu>
 <20160309170846.GA14926@infradead.org>
 <881149974.3314758.1457608128188.JavaMail.zimbra@kalray.eu>
Message-ID: <20160310143650.GA8689@infradead.org>

On Thu, Mar 10, 2016@12:08:48PM +0100, Marta Rybczynska wrote:
> Looks like a good refactoring to me. However, it seems to me that in
> nvme_cqe_valid we should be checking for phase, not for head.

Yeah, this doesn't work as-is.  I still think that non-obvious
check should be split out into something.  Maybe just:

static inline bool nvme_cqe_valid(struct nvme_queue *nvmeq, u16 head, u16 phase)
{
	return (le16_to_cpu(nvmeq->cqes[head].status) & 1) == phase;
}