linux-kernel - Re: [PATCH net-next v3] net: dsa: mv88e6xxx: Prevent suspend to RAM

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Message-ID: <20190408215540.GA27929@amd>
Date:   Mon, 8 Apr 2019 23:55:41 +0200
From:   Pavel Machek <pavel@....cz>
To:     Miquel Raynal <miquel.raynal@...tlin.com>
Cc:     Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        Gregory Clement <gregory.clement@...tlin.com>,
        Antoine Tenart <antoine.tenart@...tlin.com>,
        Maxime Chevallier <maxime.chevallier@...tlin.com>,
        Nadav Haklai <nadavh@...vell.com>
Subject: Re: [PATCH net-next v3] net: dsa: mv88e6xxx: Prevent suspend to RAM

On Tue 2019-02-05 12:07:28, Miquel Raynal wrote:
> On one hand, the mv88e6xxx driver has a work queue called in loop
> which will attempt register accesses after MDIO bus suspension, that
> entirely freezes the platform during suspend.
> 
> On the other hand, the DSA core is not ready yet to support suspend to
> RAM operation because so far there is no way to recover reliably the
> switch configuration.
> 
> To avoid the kernel to freeze when suspending with a switch driven by
> the mv88e6xxx driver, we choose to prevent the driver suspension and
> in the same way, the whole platform.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@...tlin.com>

Could we at least do printk() so that user knows what went wrong?

Debugging s2ram is usually not easy :-(.
								Pavel
 
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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