From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261822AbUCKXAT (ORCPT ); Thu, 11 Mar 2004 18:00:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261806AbUCKXAT (ORCPT ); Thu, 11 Mar 2004 18:00:19 -0500 Received: from fed1mtao06.cox.net ([68.6.19.125]:50652 "EHLO fed1mtao06.cox.net") by vger.kernel.org with ESMTP id S261824AbUCKXAG (ORCPT ); Thu, 11 Mar 2004 18:00:06 -0500 Date: Thu, 11 Mar 2004 16:00:05 -0700 From: Tom Rini To: George Anzinger Cc: "Amit S. Kale" , Pavel Machek , Kernel Mailing List , kgdb-bugreport@lists.sourceforge.net Subject: Re: [Kgdb-bugreport] [PATCH] Kill kgdb_serial Message-ID: <20040311230004.GN5169@smtp.west.cox.net> References: <20040302213901.GF20227@smtp.west.cox.net> <200403031113.02822.amitkale@emsyssoft.com> <20040303151628.GQ20227@smtp.west.cox.net> <200403041011.39467.amitkale@emsyssoft.com> <20040304152729.GC26065@smtp.west.cox.net> <4047B67A.4050609@mvista.com> <20040304231737.GJ26065@smtp.west.cox.net> <4050DB34.8060704@mvista.com> <20040311223321.GL5169@smtp.west.cox.net> <4050EDEE.6050706@mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4050EDEE.6050706@mvista.com> User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 11, 2004 at 02:53:34PM -0800, George Anzinger wrote: > Tom Rini wrote: > >On Thu, Mar 11, 2004 at 01:33:40PM -0800, George Anzinger wrote: > >>Tom Rini wrote: > >>>>I am afraid I don't quite understand what he was saying other than > >>>>early init stuff. On of the problems with trying early init stuff, by > >>>>the way, is that a lot of things depend on having alloc up and that > >>>>happens rather late in the game. > >>> > >>>I assume you aren't talking about kgdb stuff here (or what would be the > >>>point of going so early) but I believe he was talking about allowing for > >>>stuff that could be done early, to be done early. > >> > >>One of the issues with the UART set up is registering the interrupt > >>handler with the kernel. It will fail if alloc is not up. The -mm patch > >>does two things with this. a) It tries every getchar to register the > >>interrupt handler, and b) it has a module init entry to register it. > >>This last will happen late in the bring up and is safe. a) is there to > >>get it ASAP if you are actually using kgdb during the bring up. > > > > > >There's two ways to look at this. > >- All the more reason to acknowledge that the earliest you can safely > > get into KGDB is point X, where X is where alloc works, > > Just to get ^C to work? I would rather give it up entirely! > > mappings done > > if needed, etc, etc, and IFF we change things slightly in kgdboe so > > that it can call kgdb_schedule_breakpoint() if it needs to as an > > initial break, and handle setting kgdb_serial to the serial driver in > > kgdb_arch_init, or something, and remove all of the extra kludges to > > get us a few lines / function calls earlier on. > >- More and more special cases. > > How about a command line set up ASAP which calls a driver entry to do the > break. The driver being serial does it NOW, but being some thing that > needs additional resources, just sets a flag to break when it gets them and > returns. Seems rather simple. This sounds a lot like what I passed along from dwmw2 a week ago. :) -- Tom Rini http://gate.crashing.org/~trini/