From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sarah Sharp Subject: Re: net/usb/ax88179_178a driver broken in linux-3.12 Date: Wed, 20 Nov 2013 08:54:20 -0800 Message-ID: <20131120165420.GD9611@xanatos> References: <528A9A36.50903@pobox.com> <20131119.161313.743887333007019981.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , mlord@pobox.com, eric.dumazet@gmail.com, ming.lei@canonical.com, netdev@vger.kernel.org, linux-usb@vger.kernel.org To: David Laight Return-path: Received: from mga09.intel.com ([134.134.136.24]:40774 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753953Ab3KTQyV (ORCPT ); Wed, 20 Nov 2013 11:54:21 -0500 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Nov 20, 2013 at 09:54:02AM -0000, David Laight wrote: > > From: Of David Miller > > > From: "David Laight" > > > Date: Tue, 19 Nov 2013 10:04:11 -0000 > > > > > There is a patch to xhci-ring.c that should fix the SG problem. > > > http://www.spinics.net/lists/linux-usb/msg97176.html > > > > > > I think it should apply to the 3.12 sources. > > > > David, please get this into Linus's tree and queued up for -stable > > as soon as possible, thank you. > > What do I have to do to expedite it? > I thought that Sarah would have to push the patch through. Yes, I think the patch should come through my tree. > It might be necessary to limit the number of SG fragments that > the mass storage (etc) can generate to 63 (from unlimited). > That should be a 1 line change somewhere. Greg's USB tree is frozen until after 3.13-rc1. The patch will have to wait until then, but it will be marked for stable. I have no objection to the methodology of the patch, but we do need to figure out how to limit the number of scatter-gather list entries in the mass storage driver. We're still figuring out the exact limitation we need to use, and then the patch can be queued in my for-usb-linus branch for 3.13-rc1. Note that the patch is a bandaid fix, and will only help bulk endpoints that are submitting scatter-gather transfers. Interrupt endpoints using scatter-gather will still run into these issues, but with David's patch, the URB submission will now fail, rather than allowing the transfer to be silently corrupted. The real fix for this will probably be too large for stable, and is likely to take at least a kernel revision to fix. Sarah Sharp