From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?Q?Bj=C3=B8rn_Mork?= Subject: Re: PROBLEM: usbnet / ax88179_178a: Panic in usb_hcd_map_urb_for_dma Date: Fri, 10 Jan 2014 23:09:08 +0100 Message-ID: <87ob3j1ocb.fsf@nemi.mork.no> References: <1389385824.2025.95.camel@bwh-desktop.uk.level5networks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Thomas Kear , netdev , To: Ben Hutchings Return-path: In-Reply-To: <1389385824.2025.95.camel-/LGg1Z1CJKQ+9kgCwbf1HqK4ta4zdZpAajtMo4Cw6ucAvxtiuMwx3w@public.gmane.org> (Ben Hutchings's message of "Fri, 10 Jan 2014 20:30:24 +0000") Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org Ben Hutchings writes: > On Sat, 2014-01-11 at 08:56 +1300, Thomas Kear wrote: >> USB3 gigabit ethernet adapters with the ASIX AX88179 chipset (LevelO= ne >> USB0401-V3, Plugable USB3-E1000, SIIG JU-NE0211-S1 and others) are >> experiencing kernel panics in usb_hcd_map_urb_for_dma since 3.12. > [...] >> So far as I can tell, the driver is unaffected as late as 3.11.6, bu= t >> problematic as of 3.12 (and still affected in 3.13-rc5). The histor= y >> of drivers/net/usb/ax88179_178a.c for this time period yields this >> patch, which at least in my somewhat limited understanding appeared = a >> likely candidate. I've reverted this on my system - against several >> linux-next builds from the last 3-4 weeks - and have had no issues >> with this network controller since. >>=20 >> commit 3804fad45411b48233b48003e33a78f290d227c8 >> Author: Ming Lei >> Date: Thu Aug 8 21:48:25 2013 +0800 >>=20 >> USBNET: ax88179_178a: enable tso if usb host supports sg dma > > Enabling SG DMA here has unfortunately caused a number of regressions= as > the XHCI (USB 3 controller) hardware is a bit inflexible and the driv= er > wasn't quite ready to handle the SG lists generated for net devices. > > I don't think I've seen this particular symptom though, and it might > indicate a bug in usbnet. Yes, I believe this code in usbnet is still somewhat unmature and not much tested. Unfortunately I don't have any PC with xhci, so I can't d= o much about that. But looking at the code I think I found and obvious miss in the SG list initialisation. I'll post a proposed fix for that. Would be good if someone was able to test it. Bj=C3=B8rn -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html