From: Andrew Lunn <andrew@lunn•ch>
To: "Allan W. Nielsen" <allan.nielsen@microsemi•com>
Cc: Florian Fainelli <f.fainelli@gmail•com>,
netdev@vger•kernel.org, davem@davemloft•net,
bcm-kernel-feedback-list@broadcom•com,
raju.lakkaraju@microsemi•com,
vivien.didelot@savoirfairelinux•com
Subject: Re: [PATCH net-next 4/5] net: phy: bcm7xxx: Add support for downshift/Wirespeed
Date: Wed, 23 Nov 2016 15:46:36 +0100 [thread overview]
Message-ID: <20161123144636.GK14947@lunn.ch> (raw)
In-Reply-To: <20161123114512.GB25778@microsemi.com>
> > > Maybe we should think about this locking a bit. It is normal for the
> > > lock to be held when using ops in the phy driver structure. The
> > > exception is suspend/resume. Maybe we should also take the lock before
> > > calling the phydev->drv->get_tunable() and phydev->drv->set_tunable()?
> >
> > Yes, that certainly seems like a good approach to me, let me cook a
> > patch doing that.
>
> Just for my understanding (such that I will not make the same mistake again)...
>
> Why is it that phy functions such as get_wol needs to take the phy_lock and
> others like get_tunable does not.
>
> I do understand the arguments on why the lock should be held by the caller of
> get_tunable, but I do not understand why the same argument does not apply for
> get_wol.
Hi Allan
phy_ethtool_get_wol and friends probably should take the
phy_lock. This inconsistency is probably leading to locking
bugs. e.g. at803x_set_wol() does a read-modify-write, and does not
take the lock.
There is no comment in the patch adding phy_ethtool_set_wol() to say
why the lock is not taken, and a quick look at the code does not
suggest a reason why it could not be taken/released by
phy_ethtool_set_wol().
I think it would be a good idea to change this.
phy_suspend()/phy_resume() might have good reasons to avoid the lock,
i've no idea how it is supposed to work. Is there a danger something
else is holding the lock and has already been suspended? I guess not,
otherwise there is little hope suspend would work at all.
Andrew
next prev parent reply other threads:[~2016-11-23 14:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-22 19:40 [PATCH net-next 0/5] net: phy: broadcom: Wirespeed/downshift support Florian Fainelli
2016-11-22 19:40 ` [PATCH net-next 1/5] net: phy: broadcom: Move bcm54xx_auxctl_{read,write} to common library Florian Fainelli
2016-11-22 19:40 ` [PATCH net-next 2/5] net: phy: broadcom: Add support code for downshift/Wirespeed Florian Fainelli
2016-11-22 19:40 ` [PATCH net-next 3/5] net: phy: broadcom: Allow enabling or disabling of EEE Florian Fainelli
2016-11-22 19:40 ` [PATCH net-next 4/5] net: phy: bcm7xxx: Add support for downshift/Wirespeed Florian Fainelli
2016-11-22 20:02 ` Andrew Lunn
2016-11-22 20:07 ` Florian Fainelli
2016-11-22 20:57 ` Andrew Lunn
2016-11-22 21:01 ` Florian Fainelli
2016-11-23 11:45 ` Allan W. Nielsen
2016-11-23 14:46 ` Andrew Lunn [this message]
2016-11-23 18:16 ` Florian Fainelli
2016-11-22 19:40 ` [PATCH net-next 5/5] net: dsa: bcm_sf2: Ensure we re-negotiate EEE during after link change Florian Fainelli
2016-11-24 20:54 ` [PATCH net-next 0/5] net: phy: broadcom: Wirespeed/downshift support David Miller
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