From: Oliver Neukum <oneukum@suse.com>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
'Linux Samsung SOC' <linux-samsung-soc@vger.kernel.org>,
Linux USB Mailing List <linux-usb@vger.kernel.org>,
netdev@vger.kernel.org, Dean Jenkins <Dean_Jenkins@mentor.com>
Subject: Re: inconsistent lock state with usbnet/asix usb ethernet and xhci
Date: Mon, 05 Mar 2018 12:46:07 +0100 [thread overview]
Message-ID: <1520250367.3990.9.camel@suse.com> (raw)
In-Reply-To: <02679502-cf6e-8714-e879-50a922c5d976@samsung.com>
On Mon, 2018-03-05 at 08:45 +0100, Marek Szyprowski wrote:
> Hi Oliver,
>
> On 2018-02-27 17:07, Oliver Neukum wrote:
> > Am Dienstag, den 27.02.2018, 07:13 -0800 schrieb Eric Dumazet:
> >> On Tue, 2018-02-27 at 07:09 -0800, Eric Dumazet wrote:
> >>>
> >>> Note that for this one, it seems we also could perform stats updates in
> >>> BH context, since skb is queued via defer_bh()
> >>>
> >>> But simplicity wins I guess.
> >> Thinking more about this, I am not sure we have any guarantee that TX
> >> and RX can not run on multiple cpus.
> >>
> >> Using an unique syncp is not going to be safe, even if we make lockdep
> >> happy enough with the local_irq save/restore.
> > Unfortunately you are right. It is not guaranteed for some hardware.
>
> Does it mean that the fix proposed by Eric is not the proper solution?
For asix it should work, but asix is unlikely to be the only driver
with that issue. 32 bit recieves less testing nowadays.
Regards
Oliver
WARNING: multiple messages have this Message-ID (diff)
From: Oliver Neukum <oneukum@suse.com>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
'Linux Samsung SOC' <linux-samsung-soc@vger.kernel.org>,
Linux USB Mailing List <linux-usb@vger.kernel.org>,
netdev@vger.kernel.org, Dean Jenkins <Dean_Jenkins@mentor.com>
Subject: inconsistent lock state with usbnet/asix usb ethernet and xhci
Date: Mon, 05 Mar 2018 12:46:07 +0100 [thread overview]
Message-ID: <1520250367.3990.9.camel@suse.com> (raw)
On Mon, 2018-03-05 at 08:45 +0100, Marek Szyprowski wrote:
> Hi Oliver,
>
> On 2018-02-27 17:07, Oliver Neukum wrote:
> > Am Dienstag, den 27.02.2018, 07:13 -0800 schrieb Eric Dumazet:
> >> On Tue, 2018-02-27 at 07:09 -0800, Eric Dumazet wrote:
> >>>
> >>> Note that for this one, it seems we also could perform stats updates in
> >>> BH context, since skb is queued via defer_bh()
> >>>
> >>> But simplicity wins I guess.
> >> Thinking more about this, I am not sure we have any guarantee that TX
> >> and RX can not run on multiple cpus.
> >>
> >> Using an unique syncp is not going to be safe, even if we make lockdep
> >> happy enough with the local_irq save/restore.
> > Unfortunately you are right. It is not guaranteed for some hardware.
>
> Does it mean that the fix proposed by Eric is not the proper solution?
For asix it should work, but asix is unlikely to be the only driver
with that issue. 32 bit recieves less testing nowadays.
Regards
Oliver
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next prev parent reply other threads:[~2018-03-05 11:46 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20180227072602eucas1p28dcdba711b3153820bd409d838cc63bd@eucas1p2.samsung.com>
2018-02-27 7:26 ` inconsistent lock state with usbnet/asix usb ethernet and xhci Marek Szyprowski
2018-02-27 10:37 ` Oliver Neukum
2018-02-27 10:59 ` Marek Szyprowski
2018-02-27 14:07 ` Eric Dumazet
2018-02-27 14:07 ` Eric Dumazet
2018-02-27 14:42 ` Marek Szyprowski
2018-02-27 14:42 ` Marek Szyprowski
2018-02-27 15:09 ` Eric Dumazet
2018-02-27 15:09 ` Eric Dumazet
2018-02-27 15:13 ` Eric Dumazet
2018-02-27 15:13 ` Eric Dumazet
2018-02-27 16:07 ` Oliver Neukum
2018-02-27 16:07 ` Oliver Neukum
2018-03-05 7:45 ` Marek Szyprowski
2018-03-05 7:45 ` Marek Szyprowski
2018-03-05 11:46 ` Oliver Neukum [this message]
2018-03-05 11:46 ` Oliver Neukum
2018-03-05 19:09 ` Eric Dumazet
2018-03-05 19:09 ` Eric Dumazet
2018-03-05 19:41 [net] net: usbnet: fix potential deadlock on 32bit hosts Eric Dumazet
2018-03-05 19:41 ` [PATCH net] " Eric Dumazet
-- strict thread matches above, loose matches on Subject: below --
2018-03-07 16:47 [net] " David Miller
2018-03-07 16:47 ` [PATCH net] " David Miller
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