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From: Jens Axboe <axboe@fb.com>
To: Wenbo Wang <mail_weber_wang@163.com>, <keith.busch@intel.com>
Cc: <linux-kernel@vger.kernel.org>,
	Wenbo Wang <wenbo.wang@memblaze.com>,
	<linux-nvme@lists.infradead.org>
Subject: Re: [PATCH] NVMe: do not touch sq door bell if nvmeq has been suspended
Date: Mon, 1 Feb 2016 09:54:13 -0700	[thread overview]
Message-ID: <56AF8DB5.70206@fb.com> (raw)
In-Reply-To: <1454341324-21273-1-git-send-email-mail_weber_wang@163.com>

On 02/01/2016 08:42 AM, Wenbo Wang wrote:
> If __nvme_submit_cmd races with nvme_dev_disable, nvmeq
> could have been suspended and dev->bar could have been
> unmapped. Do not touch sq door bell in this case.
>
> Signed-off-by: Wenbo Wang <wenbo.wang@memblaze.com>
> Reviewed-by: Wenwei Tao <wenwei.tao@memblaze.com>
> CC: linux-nvme@lists.infradead.org
> ---
>   drivers/nvme/host/pci.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 8b1a725..2288712 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -325,7 +325,8 @@ static void __nvme_submit_cmd(struct nvme_queue *nvmeq,
>
>   	if (++tail == nvmeq->q_depth)
>   		tail = 0;
> -	writel(tail, nvmeq->q_db);
> +	if (likely(nvmeq->cq_vector >= 0))
> +		writel(tail, nvmeq->q_db);
>   	nvmeq->sq_tail = tail;

What Keith said (this should not happen), and additionally, this won't 
work for a polled CQ without a vector.

-- 
Jens Axboe

WARNING: multiple messages have this Message-ID (diff)
From: axboe@fb.com (Jens Axboe)
Subject: [PATCH] NVMe: do not touch sq door bell if nvmeq has been suspended
Date: Mon, 1 Feb 2016 09:54:13 -0700	[thread overview]
Message-ID: <56AF8DB5.70206@fb.com> (raw)
In-Reply-To: <1454341324-21273-1-git-send-email-mail_weber_wang@163.com>

On 02/01/2016 08:42 AM, Wenbo Wang wrote:
> If __nvme_submit_cmd races with nvme_dev_disable, nvmeq
> could have been suspended and dev->bar could have been
> unmapped. Do not touch sq door bell in this case.
>
> Signed-off-by: Wenbo Wang <wenbo.wang at memblaze.com>
> Reviewed-by: Wenwei Tao <wenwei.tao at memblaze.com>
> CC: linux-nvme at lists.infradead.org
> ---
>   drivers/nvme/host/pci.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 8b1a725..2288712 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -325,7 +325,8 @@ static void __nvme_submit_cmd(struct nvme_queue *nvmeq,
>
>   	if (++tail == nvmeq->q_depth)
>   		tail = 0;
> -	writel(tail, nvmeq->q_db);
> +	if (likely(nvmeq->cq_vector >= 0))
> +		writel(tail, nvmeq->q_db);
>   	nvmeq->sq_tail = tail;

What Keith said (this should not happen), and additionally, this won't 
work for a polled CQ without a vector.

-- 
Jens Axboe

  parent reply	other threads:[~2016-02-01 16:57 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-01 15:42 [PATCH] NVMe: do not touch sq door bell if nvmeq has been suspended Wenbo Wang
2016-02-01 15:42 ` Wenbo Wang
2016-02-01 15:59 ` Busch, Keith
2016-02-01 15:59   ` Busch, Keith
2016-02-01 16:17   ` Wenbo Wang
2016-02-01 16:17     ` Wenbo Wang
2016-02-01 16:54 ` Jens Axboe [this message]
2016-02-01 16:54   ` Jens Axboe
2016-02-02  7:15   ` Wenbo Wang
2016-02-02 12:41     ` Sagi Grimberg
2016-02-02 12:41       ` Sagi Grimberg
2016-02-02 14:27       ` Keith Busch
2016-02-02 14:27         ` Keith Busch
2016-02-02 14:33         ` Sagi Grimberg
2016-02-02 14:33           ` Sagi Grimberg
2016-02-02 14:46           ` Keith Busch
2016-02-02 14:46             ` Keith Busch
2016-02-02 17:20             ` Sagi Grimberg
2016-02-02 17:20               ` Sagi Grimberg
2016-02-03  0:49               ` Wenbo Wang
2016-02-02 17:25     ` Keith Busch
2016-02-02 17:25       ` Keith Busch
2016-02-03  0:19       ` Wenbo Wang
2016-02-03 14:41     ` Keith Busch
2016-02-03 14:41       ` Keith Busch
2016-02-03 16:35       ` Wenbo Wang
2016-02-03 16:38         ` Keith Busch
2016-02-03 16:38           ` Keith Busch
2016-02-06 14:32           ` Wenbo Wang
2016-02-07 13:41             ` Sagi Grimberg
2016-02-07 13:41               ` Sagi Grimberg
2016-02-08 15:01             ` Keith Busch
2016-02-08 15:01               ` Keith Busch
2016-02-09 11:22               ` Wenbo Wang
2016-02-09 22:55                 ` Keith Busch
2016-02-09 22:55                   ` Keith Busch

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