From: Florian Fainelli <f.fainelli@gmail.com>
To: Ansuel Smith <ansuelsmth@gmail.com>, Andrew Lunn <andrew@lunn.ch>,
Vivien Didelot <vivien.didelot@gmail.com>,
Vladimir Oltean <olteanv@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Cc: Vladimir Oltean <vladimir.oltean@nxp.com>
Subject: Re: [RFC PATCH v7 02/16] net: dsa: replay master state events in dsa_tree_{setup,teardown}_master
Date: Tue, 25 Jan 2022 19:27:35 -0800 [thread overview]
Message-ID: <cba946ff-5ba4-b2af-118c-b1d0a7669450@gmail.com> (raw)
In-Reply-To: <20220123013337.20945-3-ansuelsmth@gmail.com>
On 1/22/2022 5:33 PM, Ansuel Smith wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
>
> In order for switch driver to be able to make simple and reliable use of
> the master tracking operations, they must also be notified of the
> initial state of the DSA master, not just of the changes. This is
> because they might enable certain features only during the time when
> they know that the DSA master is up and running.
>
> Therefore, this change explicitly checks the state of the DSA master
> under the same rtnl_mutex as we were holding during the
> dsa_master_setup() and dsa_master_teardown() call. The idea being that
> if the DSA master became operational in between the moment in which it
> became a DSA master (dsa_master_setup set dev->dsa_ptr) and the moment
> when we checked for the master being up, there is a chance that we
> would emit a ->master_state_change() call with no actual state change.
> We need to avoid that by serializing the concurrent netdevice event with
> us. If the netdevice event started before, we force it to finish before
> we begin, because we take rtnl_lock before making netdev_uses_dsa()
> return true. So we also handle that early event and do nothing on it.
> Similarly, if the dev_open() attempt is concurrent with us, it will
> attempt to take the rtnl_mutex, but we're holding it. We'll see that
> the master flag IFF_UP isn't set, then when we release the rtnl_mutex
> we'll process the NETDEV_UP notifier.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
--
Florian
next prev parent reply other threads:[~2022-01-26 3:27 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-23 1:33 [RFC PATCH v7 00/16] Add support for qca8k mdio rw in Ethernet packet Ansuel Smith
2022-01-23 1:33 ` [RFC PATCH v7 01/16] net: dsa: provide switch operations for tracking the master state Ansuel Smith
2022-01-26 3:22 ` Florian Fainelli
2022-01-26 21:00 ` Vladimir Oltean
2022-01-23 1:33 ` [RFC PATCH v7 02/16] net: dsa: replay master state events in dsa_tree_{setup,teardown}_master Ansuel Smith
2022-01-26 3:27 ` Florian Fainelli [this message]
2022-01-23 1:33 ` [RFC PATCH v7 03/16] net: dsa: tag_qca: convert to FIELD macro Ansuel Smith
2022-01-24 16:00 ` Vladimir Oltean
2022-01-26 3:28 ` Florian Fainelli
2022-01-23 1:33 ` [RFC PATCH v7 04/16] net: dsa: tag_qca: move define to include linux/dsa Ansuel Smith
2022-01-24 15:59 ` Vladimir Oltean
2022-01-26 3:28 ` Florian Fainelli
2022-01-23 1:33 ` [RFC PATCH v7 05/16] net: dsa: tag_qca: enable promisc_on_master flag Ansuel Smith
2022-01-26 3:28 ` Florian Fainelli
2022-01-23 1:33 ` [RFC PATCH v7 06/16] net: dsa: tag_qca: add define for handling mgmt Ethernet packet Ansuel Smith
2022-01-24 16:05 ` Vladimir Oltean
2022-01-24 16:16 ` Ansuel Smith
2022-01-26 3:54 ` Florian Fainelli
2022-01-26 4:01 ` Ansuel Smith
2022-01-26 4:02 ` Florian Fainelli
2022-01-26 4:05 ` Ansuel Smith
2022-01-26 3:57 ` Florian Fainelli
2022-01-23 1:33 ` [RFC PATCH v7 07/16] net: dsa: tag_qca: add define for handling MIB packet Ansuel Smith
2022-01-23 1:33 ` [RFC PATCH v7 08/16] net: dsa: tag_qca: add support for handling mgmt and MIB Ethernet packet Ansuel Smith
2022-01-24 16:08 ` Vladimir Oltean
2022-01-26 3:34 ` Florian Fainelli
2022-01-23 1:33 ` [RFC PATCH v7 09/16] net: dsa: qca8k: add tracking state of master port Ansuel Smith
2022-01-26 3:37 ` Florian Fainelli
2022-01-23 1:33 ` [RFC PATCH v7 10/16] net: dsa: qca8k: add support for mgmt read/write in Ethernet packet Ansuel Smith
2022-01-24 16:32 ` Vladimir Oltean
2022-01-24 16:48 ` Ansuel Smith
2022-01-25 14:54 ` Vladimir Oltean
2022-01-23 1:33 ` [RFC PATCH v7 11/16] net: dsa: qca8k: add support for mib autocast " Ansuel Smith
2022-01-25 15:12 ` Vladimir Oltean
2022-01-23 1:33 ` [RFC PATCH v7 12/16] net: dsa: qca8k: add support for phy read/write with mgmt Ethernet Ansuel Smith
2022-01-25 15:03 ` Vladimir Oltean
2022-01-25 23:14 ` Ansuel Smith
2022-01-26 1:48 ` Vladimir Oltean
2022-01-26 1:57 ` Ansuel Smith
2022-01-26 22:05 ` Vladimir Oltean
2022-01-23 1:33 ` [RFC PATCH v7 13/16] net: dsa: qca8k: move page cache to driver priv Ansuel Smith
2022-01-26 3:50 ` Florian Fainelli
2022-02-01 21:39 ` Ansuel Smith
2022-01-23 1:33 ` [RFC PATCH v7 14/16] net: dsa: qca8k: cache lo and hi for mdio write Ansuel Smith
2022-01-26 3:42 ` Florian Fainelli
2022-01-23 1:33 ` [RFC PATCH v7 15/16] net: da: qca8k: add support for larger read/write size with mgmt Ethernet Ansuel Smith
2022-01-26 3:48 ` Florian Fainelli
2022-01-26 3:57 ` Ansuel Smith
2022-01-23 1:33 ` [RFC PATCH v7 16/16] net: dsa: qca8k: introduce qca8k_bulk_read/write function Ansuel Smith
2022-01-26 3:45 ` Florian Fainelli
2022-01-26 3:53 ` Ansuel Smith
2022-01-30 13:59 ` [RFC PATCH v7 00/16] Add support for qca8k mdio rw in Ethernet packet Ansuel Smith
2022-01-30 17:07 ` Florian Fainelli
2022-02-03 17:59 ` Ansuel Smith
2022-02-03 18:21 ` Vladimir Oltean
2022-02-03 20:10 ` Jakub Kicinski
2022-02-03 20:31 ` Ansuel Smith
2022-02-03 21:25 ` Vladimir Oltean
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