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From: Florian Fainelli <f.fainelli@gmail.com>
To: Vladimir Oltean <vladimir.oltean@nxp.com>,
	"David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org, UNGLinuxDriver@microchip.com,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Horatiu Vultur <horatiu.vultur@microchip.com>,
	"Allan W . Nielsen" <allan.nielsen@microchip.com>,
	Claudiu Manoil <claudiu.manoil@nxp.com>,
	Steen Hegelund <steen.hegelund@microchip.com>
Subject: Re: [PATCH net] net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context
Date: Fri, 4 Dec 2020 09:34:54 -0800	[thread overview]
Message-ID: <ae82dc10-11af-e48a-a317-fc60cda3b993@gmail.com> (raw)
In-Reply-To: <20201204170938.1415582-1-vladimir.oltean@nxp.com>



On 12/4/2020 9:09 AM, Vladimir Oltean wrote:
> Currently ocelot_set_rx_mode calls ocelot_mact_learn directly, which has
> a very nice ocelot_mact_wait_for_completion at the end. Introduced in
> commit 639c1b2625af ("net: mscc: ocelot: Register poll timeout should be
> wall time not attempts"), this function uses readx_poll_timeout which
> triggers a lot of lockdep warnings and is also dangerous to use from
> atomic context, leading to lockups and panics.
> 
> Steen Hegelund added a poll timeout of 100 ms for checking the MAC
> table, a duration which is clearly absurd to poll in atomic context.
> So we need to defer the MAC table access to process context, which we do
> via a dynamically allocated workqueue which contains all there is to
> know about the MAC table operation it has to do.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

Did you want to have a Fixes tag to help identify how far back this
needs to be back ported?
-- 
Florian

  reply	other threads:[~2020-12-04 17:36 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-04 17:09 [PATCH net] net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context Vladimir Oltean
2020-12-04 17:34 ` Florian Fainelli [this message]
2020-12-04 17:40   ` Vladimir Oltean

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