From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas@monjalon.net>
Subject: Re: [PATCH v2] doc: update API deprecation for device
	reset
Date: Mon, 28 Jan 2019 01:20:24 +0100
Message-ID: <1648146.NeMYav50z5@xps>
References: <20180920045959.106252-1-qi.z.zhang@intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7Bit
Cc: dev@dpdk.org, declan.doherty@intel.com, ferruh.yigit@intel.com,
 ktraynor@redhat.com, benjamin.h.shelton@intel.com, narender.vangati@intel.com
To: Qi Zhang <qi.z.zhang@intel.com>
Return-path: <dev-bounces@dpdk.org>
Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com
 [66.111.4.29]) by dpdk.org (Postfix) with ESMTP id 1C609316B
 for <dev@dpdk.org>; Mon, 28 Jan 2019 01:20:28 +0100 (CET)
In-Reply-To: <20180920045959.106252-1-qi.z.zhang@intel.com>
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

Hi,

I don't remember why this deprecation notice did not get any feedback
in the 18.11 cycle. It looks to be outdated now.
In case you still plan some changes, I give my opinion below.

20/09/2018 06:59, Qi Zhang:
> Device reset may have the dependency, for example, a VF reset expects
> PF ready, or a NIC function as a part of a SOC need to wait for other
> parts of the system be ready, these are time-consuming tasks and will
> block current thread.
> 
> So we rename rte_eth_dev_reset to rte_eth_dev_reset_async as an async
> API, that makes things easy for an application that what to reset the
> device from the interrupt thread since typically a
> RTE_ETH_EVENT_INTR_RESET handler is invoked in interrupt thread.
> 
> RFC patch:
> http://patchwork.dpdk.org/patch/44989/
> 
> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>

I remmember I did not like this function when it was introduced.
I think the cases addressed by rte_eth_dev_reset() should be handled
with hotplug mechanism.

> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> +* ethdev: In v19.02 ``rte_eth_dev_reset`` is renamed to

Is it still planned for 19.05?

> +  ``rte_eth_dev_reset_async``. As the name, it is an async API.

Why removing the old function?
We could avoid breaking applications by adding an async flavor
of the function.

> +  Application should not assume device reset is finished after
> +  ``rte_eth_dev_reset_async`` return, it should always wait for a
> +  RTE_ETH_EVENT_RESET_COMPLETE event and check the reset result.

This could be done in the synchronous flavor with sleeps in a loop.