From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: net/usb/ax88179_178a driver broken in linux-3.12 Date: Mon, 18 Nov 2013 17:52:38 -0500 Message-ID: <528A9A36.50903@pobox.com> References: <52890C7E.6000607@pobox.com> <52891178.2080509@pobox.com> <52891341.4020403@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit To: David Laight , Eric Dumazet , Ming Lei , davem@davemloft.net, netdev@vger.kernel.org Return-path: Received: from a-pb-sasl-quonix.pobox.com ([208.72.237.25]:53554 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751171Ab3KRWwk (ORCPT ); Mon, 18 Nov 2013 17:52:40 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 13-11-18 08:32 AM, David Laight wrote: >> From: David Laight >>> On 13-11-17 01:56 PM, Mark Lord wrote: >>>> On 13-11-17 01:35 PM, Mark Lord wrote: >>>>> The USB3 network adapter locks up consistently for me here in 3.12, >>>>> but was working without issues in 3.11.x >> >> The xhci driver is well broken in 3.12. > > To correct myself... > > The xhci driver has never correctly support scatter-gather requests. > In 3.12 code was added to usbnet to generate SG transmits, and to the > ax88179_178a driver to use them. > TCP segmentation offload was then enabled - with does generate > SG transfers. > > SG transfers for 'disks' almost certainly work because the > fragment boundaries are 'adequately aligned'. > > David > Well, that's all very nice and whatnot, except the ax88179_178a driver still does not work in linux-3.12, whereas it works fine in all earlier kernels. That's a regression. And a simple revert (earlier in this thread) fixes it. So.. let's revert it for now, until a proper xhci compatible patch is produced. -- Mark Lord Real-Time Remedies Inc. mlord@pobox.com