From: keith.busch@intel.com (Keith Busch)
Subject: [PATCH v2] Bugfix for handling of shadow doorbell buffer.
Date: Thu, 16 Aug 2018 08:15:59 -0600 [thread overview]
Message-ID: <20180816141558.GB5438@localhost.localdomain> (raw)
In-Reply-To: <20180815225157.89523-1-wnukowski@google.com>
On Wed, Aug 15, 2018@03:51:57PM -0700, Michal Wnukowski wrote:
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 17a0190bd88f..4452f8553301 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -306,6 +306,14 @@ static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db,
> old_value = *dbbuf_db;
> *dbbuf_db = value;
>
> + /*
> + * Ensure that the doorbell is updated before reading
> + * the EventIdx from memory. NVMe controller should have
> + * similar ordering guarantees - update EventIdx before
> + * reading doorbell.
> + */
> + mb();
> +
> if (!nvme_dbbuf_need_event(*dbbuf_ei, value, old_value))
> return false;
> }
Looks good to me. This should also be a stable candidate.
Reviewed-by: Keith Busch <keith.busch at intel.com>
next prev parent reply other threads:[~2018-08-16 14:15 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-14 22:17 [PATCH] Bugfix for handling of shadow doorbell buffer Michal Wnukowski
2018-08-14 22:57 ` Keith Busch
2018-08-14 23:16 ` Linus Torvalds
2018-08-14 23:49 ` Keith Busch
2018-08-15 1:35 ` Michal Wnukowski
2018-08-15 2:02 ` Linus Torvalds
2018-08-15 22:51 ` [PATCH v2] " Michal Wnukowski
2018-08-16 14:15 ` Keith Busch [this message]
2018-08-16 21:20 ` Sagi Grimberg
2018-08-17 7:07 ` Christoph Hellwig
2018-08-20 20:09 ` Michal Wnukowski
2018-08-17 7:10 ` [PATCH] " Christoph Hellwig
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