From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752949AbaFGPkT (ORCPT ); Sat, 7 Jun 2014 11:40:19 -0400 Received: from netrider.rowland.org ([192.131.102.5]:60691 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752821AbaFGPkR (ORCPT ); Sat, 7 Jun 2014 11:40:17 -0400 Date: Sat, 7 Jun 2014 11:40:15 -0400 (EDT) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: Benjamin Herrenschmidt cc: Thadeu Lima de Souza Cascardo , linux-usb , Kernel development list , Greg KH , Sarah Sharp , Mathias Nyman Subject: Re: Missing USB XHCI and EHCI reset for kexec In-Reply-To: <1402128942.3247.292.camel@pasglop> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Added Mathias to CC: list] On Sat, 7 Jun 2014, Benjamin Herrenschmidt wrote: > I'm trying to kexec from our OPAL FW bootloader (3.10.23 based) to a > fedora 3.14.3 on a new machine and am still seeing the above. > > A reset brings the chip back. > > Do we have any resolution here ? It looks like the xHCI remains active > on the way out and is clagged up on the way back in, at least in a > state the driver really doesn't like. > > And this is a "clean" kexec, not a forced one... This is killing USB on > the upcoming OpenPower dev machines. The current xhci-hcd driver includes a quirk flag (XHCI_SPURIOS_WAKEUP) that causes the shutdown routine to reset the controller. It wasn't meant for fixing kexec problems, but I bet you could use it for that purpose. In addition, it's possible that a reset is needed in the probe pathway. Alan Stern