From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936859AbWLEWka (ORCPT ); Tue, 5 Dec 2006 17:40:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936870AbWLEWk3 (ORCPT ); Tue, 5 Dec 2006 17:40:29 -0500 Received: from wr-out-0506.google.com ([64.233.184.230]:31357 "EHLO wr-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936859AbWLEWk2 (ORCPT ); Tue, 5 Dec 2006 17:40:28 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=l2hP5UsoZh5WeJm5/dSxjph52Beh32fU4u45k6rwsuJRgoGfAyeQAF723lZQlt7FUbrlojeOxHgcafSvO8N9EdQMp0Nfu+wd8+Lke5I/rDkgc8tEDBmjU8p/q6UvPTz5mvADvsXhEin8inpQeGYIlxCoklFeG5AKY1/G8eeHwxA= Message-ID: <9a8748490612051440v81372dcia879acdf718047bb@mail.gmail.com> Date: Tue, 5 Dec 2006 23:40:28 +0100 From: "Jesper Juhl" To: "Corey Minyard" Subject: Re: [PATCH 7/12] IPMI: add poll delay Cc: "Andrew Morton" , "Linux Kernel" , "OpenIPMI Developers" In-Reply-To: <4575779C.1050204@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20061202043520.GC30531@localdomain> <20061203132610.471786ca.akpm@osdl.org> <4575779C.1050204@acm.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 05/12/06, Corey Minyard wrote: > Andrew Morton wrote: > > On Fri, 1 Dec 2006 22:35:20 -0600 > > Corey Minyard wrote: > > > > > >> Make sure to delay a little in the IPMI poll routine so we can pass in > >> a timeout time and thus time things out. > >> > >> Signed-off-by: Corey Minyard > >> > >> Index: linux-2.6.19-rc6/drivers/char/ipmi/ipmi_si_intf.c > >> =================================================================== > >> --- linux-2.6.19-rc6.orig/drivers/char/ipmi/ipmi_si_intf.c > >> +++ linux-2.6.19-rc6/drivers/char/ipmi/ipmi_si_intf.c > >> @@ -807,7 +807,12 @@ static void poll(void *send_info) > >> { > >> struct smi_info *smi_info = send_info; > >> > >> - smi_event_handler(smi_info, 0); > >> + /* > >> + * Make sure there is some delay in the poll loop so we can > >> + * drive time forward and timeout things. > >> + */ > >> + udelay(10); > >> + smi_event_handler(smi_info, 10); > >> } > >> > > > > I don't understand what this patch is doing. It looks fishy. More > > details, please? > > > Yeah, it does look a little fishy. This is a poll routine that is only > called at panic > time; it is used to force things to happen in the driver without > scheduling or > timers. The driver does this so it can set watchdog parameters and store > panic information in the event log at panic time. > > Without this change, if something goes wrong in the BMC the driver will > never > time out the operation since it doesn't see time being driven forward. > So this > makes sure the driver sees time advancing as it should. > Hmm, I wonder if this could explain why some of my IBM servers become unreachable via IPMI after a kernel crash. -- Jesper Juhl Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please http://www.expita.com/nomime.html