Re: inconsistent lock state with usbnet/asix usb ethernet and xhci

[Marek Szyprowski]

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?

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland