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

From: Oliver Neukum <[email-masked]>
Date: Tue, 27 Feb 2018 17:07:55 +0100

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.

	Regards
		Oliver