Date: Fri, 9 Dec 2016 12:21:42 +0100
From: Pavel Machek <pavel@ucw.cz>
To: Francois Romieu <romieu@fr.zoreil.com>
Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de>, bh74.an@samsung.com,
        ks.giri@samsung.com, vipul.pandya@samsung.com, peppe.cavallaro@st.com,
        alexandre.torgue@st.com, davem@davemloft.net,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 1/2] net: ethernet: sxgbe: remove private tx queue lock
Message-ID: <20161209112142.GA22710@amd>
References: <1481141138-19466-1-git-send-email-LinoSanfilippo@gmx.de>
 <1481141138-19466-2-git-send-email-LinoSanfilippo@gmx.de>
 <20161207231534.GB5889@electric-eye.fr.zoreil.com>
 <051e3043-8b58-0591-36e3-99e2267f67f4@gmx.de>
 <20161208231943.GA13102@electric-eye.fr.zoreil.com>
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On Fri 2016-12-09 00:19:43, Francois Romieu wrote:
> Lino Sanfilippo <LinoSanfilippo@gmx.de> :
> [...]
> > OTOH Pavel said that he actually could produce a deadlock. Now I wonder=
 if
> > this is caused by that locking scheme (in a way I have not figured out =
yet)
> > or if it is a different issue.
>=20
> stmmac_tx_err races with stmmac_xmit.

Umm, yes, that looks real.

And that means that removing tx_lock will not be completely trivial
:-(. Lino, any ideas there?

netif_tx_lock_irqsave() would help, but afaict that one does not
exist.

Plus, does someone know how to trigger the status =3D=3D tx_hard_error? I
tried powering down the switch, but that did not do it.

Thanks,								Pavel

--=20
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo=
g.html

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