Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 17 Apr 2023 15:01:52 +0200
From:   Simon Horman <simon.horman@corigine.com>
To:     Vladimir Oltean <vladimir.oltean@nxp.com>
Cc:     netdev@vger.kernel.org, Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Claudiu Manoil <claudiu.manoil@nxp.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        UNGLinuxDriver@microchip.com,
        Xiaoliang Yang <xiaoliang.yang_1@nxp.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 4/7] net: mscc: ocelot: don't rely on cached
 verify_status in ocelot_port_get_mm()
Message-ID: <ZD1DQN8HlSbVC+ci@corigine.com>
References: <20230415170551.3939607-1-vladimir.oltean@nxp.com>
 <20230415170551.3939607-5-vladimir.oltean@nxp.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230415170551.3939607-5-vladimir.oltean@nxp.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?ySmzw/zoZ3YdCt1SkOa5c141oMYGc8spJDP7A90XDGP+nPX9j2JddTkeYuUW?=
 =?us-ascii?Q?DPBYP86VgWYxC+fp5RYxwpu0Uwyz550YVg1pPOo4vlm+gYCiFmSupHBU/FzI?=
 =?us-ascii?Q?g/ejCx48N+xbH+ex/c8joouJda3fNrHpIM2pnJfLlI4fSo2lsH2NdXrk7MNx?=
 =?us-ascii?Q?740XcSPoPitr4qyKBdmF+mxVlcSvgHY7dUi/bW/ZLawEvtlWIt76u+gzxuEp?=
 =?us-ascii?Q?sAvfQWX8QlNFx/D7wH5atRtw3rPoUDehNOStYO6MhzPZa+K4SYBvVJsyvio0?=
 =?us-ascii?Q?oEZAfgzvFFSWUaWWr0MzfVtqJiSk2C79JFQZD/vZfRRcE5OKG2cIASegjYPL?=
 =?us-ascii?Q?JdnIW/NPoZGvMAD1ynaVz1hJY29QwjpdoV3Zt/QHWMjgmbidHpGXHWunRKX4?=
 =?us-ascii?Q?5iDZP7UqNEWAcsbHpH9ScuGtff7tisPEp2i1KmajO7DzBWkMZzKz4so5dq0s?=
 =?us-ascii?Q?efttg8qst7rpoNhGatVQCxm86uZbjWQbQ5B+fKMojZ7IJmeTUijn/W6mK00R?=
 =?us-ascii?Q?zJ8Xq7L3748W2VMvVIEX9ErHsIZPE/WQRIXeIxSR774Fx4ZVJD1EC0eXNLfx?=
 =?us-ascii?Q?ceO+dl/suLH6rDNgAPM+CJeKsH5gfmXzg5czOxIeSsphEsW65He0ycBr7IgE?=
 =?us-ascii?Q?tWeyABR1ghh7WBc5m9n3LAX3EA+CbuKGOhVr2kINiz2HMsZWB1cfOOENKaZT?=
 =?us-ascii?Q?dtSHh2Ts4PriHP/WXz5k7L7cpT/yebrBZqoY+4MNOdOlHP55YkFtkTGTk3a/?=
 =?us-ascii?Q?obCGtn3z2eZcji9+IlVwTVNfmfSh1+idmnaRi90vGOa38ytGv1prD+RP4mK1?=
 =?us-ascii?Q?CGaiO7s7MMPTto+gipi5x+JzsnQ/mAMdFaY38xnFUMmAPuS0GQ+ApdDqxma+?=
 =?us-ascii?Q?aAdhqd6PgY7ZTlFQaPIlvhOV0flUYT8Q95ixJ7K8VOThxmZW0tr3HQyIanmm?=
 =?us-ascii?Q?SNG8YbeaWalQkHI0GJ3KG53JVKTdsjUeSEiRGZCUc0N1/OZdXo8PAZmVo9rF?=
 =?us-ascii?Q?/j//96XoBgy6u7IWdDmG0SWmItq2hPRESH6xyaIxpUncwUZEFNxQwhE7xDfA?=
 =?us-ascii?Q?QRHxlgiU8fFnoGLtnXfIACxL6FW40SXcZqyyjt04TRYq5j0NKajRy8ZCNkLA?=
 =?us-ascii?Q?TEE7ysgfmXd4Ew6DkakiaUTfVx97Aiy5hZ8iFj4O/xvVYuLfyLYC+RN9A+dq?=
 =?us-ascii?Q?fTeIQ27teoT6y0m4lWL40tJYINYEonpT5ihLl/xKdhamxNZxFyKhVDbqx1W6?=
 =?us-ascii?Q?tWPQjFDBG9HnzpJJM6NpXZBESBXtvQsTJ9N795AnyeFfFHfc8jLtMrEh3bdK?=
 =?us-ascii?Q?2dt8/Yi+o6pt9yAlyhZ0Ap7/U6jS4CaA6pPlLitLHNxnBIFCpnh9XEHYRFYH?=
 =?us-ascii?Q?jLoq0PVuA9GOCQRy9UVotgM1/2RaB/y2iknAxqZZGMonZ8fHI6VznYI5FWze?=
 =?us-ascii?Q?VDzmi4Y2Kz6Y5D5k5MMDojsOl1ZLS+fndNETduTVYsbZTIZeHSlO147enVHH?=
 =?us-ascii?Q?T33LK6A6TLH0fDX+JW2NxsfUyzmIymtNtVCf8uicVjwZAPfbIglkv3R2qivm?=
 =?us-ascii?Q?9hWWYj/vmaDuOo+ew0lR3cCvTwhmLkowGETpyzj7inqbQOuy054g2PxfaXb7?=
 =?us-ascii?Q?AGISp9TqrPIAU97w8OXzD6suu1xXEorSjrBDxHGcghBng0PpPqdiefY5+NaJ?=
 =?us-ascii?Q?5OAAtA=3D=3D?=
X-OriginatorOrg: corigine.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 2352a798-8452-46bf-301e-08db3f43edb4
X-MS-Exchange-CrossTenant-AuthSource: PH0PR13MB4842.namprd13.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Apr 2023 13:01:58.7944
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: fe128f2c-073b-4c20-818e-7246a585940c
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 6/3mVZBv1qqB2ReFdLjphQXJincv2jhUN/DVlkMQG3iNwKHPm4CTLr0WF2uvvsFPKIyXCm99haOi8vrPbFUxfirCNV6A6YXW846CO1KF/XQ=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR13MB3959
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,
        T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Sat, Apr 15, 2023 at 08:05:48PM +0300, Vladimir Oltean wrote:
> ocelot_mm_update_port_status() updates mm->verify_status, but when the
> verification state of a port changes, an IRQ isn't emitted, but rather,
> only when the verification state reaches one of the final states (like
> DISABLED, FAILED, SUCCEEDED) - things that would affect mm->tx_active,
> which is what the IRQ *is* actually emitted for.
> 
> That is to say, user space may miss reports of an intermediary MAC Merge
> verification state (like from INITIAL to VERIFYING), unless there was an
> IRQ notifying the driver of the change in mm->tx_active as well.
> 
> This is not a huge deal, but for reliable reporting to user space, let's
> call ocelot_mm_update_port_status() synchronously from
> ocelot_port_get_mm(), which makes user space see the current MM status.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Reviewed-by: Simon Horman <simon.horman@corigine.com>