From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754411AbaDNPpS (ORCPT ); Mon, 14 Apr 2014 11:45:18 -0400 Received: from www84.your-server.de ([213.133.104.84]:35719 "EHLO www84.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754239AbaDNPpM (ORCPT ); Mon, 14 Apr 2014 11:45:12 -0400 Date: Mon, 14 Apr 2014 17:44:58 +0200 Message-ID: <20140414174458.Horde.ieyRX8PcZ0lg3nY1QFE2DA4@webmail.your-server.de> From: stefani@seibold.net To: Benjamin Herrenschmidt Cc: linux-usb , linux-kernel@vger.kernel.org, Greg KH , Alan Stern , sarah.a.sharp@linux.intel.com, Thadeu Lima de Souza Cascardo Subject: Re: Missing USB XHCI and EHCI reset for kexec References: <1397416959.1555.30.camel@vger.seibold.net> <1397468521.9258.28.camel@pasglop> In-Reply-To: <1397468521.9258.28.camel@pasglop> User-Agent: Internet Messaging Program (IMP) H5 (6.1.7) Content-Type: text/plain; charset=UTF-8; format=flowed; DelSp=Yes MIME-Version: 1.0 Content-Disposition: inline X-Authenticated-Sender: stefani@seibold.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Zitat von Benjamin Herrenschmidt : > On Sun, 2014-04-13 at 21:22 +0200, Stefani Seibold wrote: >> When executing a kexec kernel on a PowerPC board the new started kernel >> will not find already enumerated USB devices due a missing reset on the >> USB bus. >> >> As a work around a >> >> echo 1 >/sys/bus/pci/drivers/[ex]hci-pci/BUS-ADDRESS-OF-THE-HCD/reset >> >> will solve this. But this is far from beauty. >> >> My latest kernel without this issue was for EHCI kernel 2.6.39 and for >> XHCI kernel 3.4, but i have no idea when exactly this behavior was >> introduced. >> >> For X86 all is fine. > > I don't know about EHCI specifically but this is a known issue with > XHCI, I observe similar issues on other powerpc platforms (servers) > and this isn't architecture specific (looks more like actualy xhc > implementation specific). > > Thadeu Cascardo (on CC) has been the one investigating that on our side, > he might have more to add including patches. > I have now a kernel 3.14 dmesg log of the problem. After a kexec the kexeced 3.14 kernel shows: [ 1.170029] xhci_hcd 0001:03:00.0: xHCI Host Controller [ 1.175306] xhci_hcd 0001:03:00.0: new USB bus registered, assigned bus number 1 [ 1.212561] xhci_hcd 0001:03:00.0: Host not halted after 16000 microseconds. [ 1.219621] xhci_hcd 0001:03:00.0: can't setup: -110 [ 1.224597] xhci_hcd 0001:03:00.0: USB bus 1 deregistered [ 1.230021] xhci_hcd 0001:03:00.0: init 0001:03:00.0 fail, -110 [ 1.235955] xhci_hcd: probe of 0001:03:00.0 failed with error -110 Any idea? - Stefani