From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from yx-out-2324.google.com (yx-out-2324.google.com [74.125.44.28]) by ozlabs.org (Postfix) with ESMTP id 1DBD9DDDFF for ; Wed, 1 Apr 2009 09:22:26 +1100 (EST) Received: by yx-out-2324.google.com with SMTP id 8so1657107yxg.39 for ; Tue, 31 Mar 2009 15:22:25 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <49D28A7E.2090703@mlbassoc.com> References: <5ee96a840903311330y36ed97bet92319da8d118086@mail.gmail.com> <49D280E0.9020701@mlbassoc.com> <5ee96a840903311403r331943d2wf9dbb16491f6bc3@mail.gmail.com> <49D28A7E.2090703@mlbassoc.com> Date: Tue, 31 Mar 2009 18:22:24 -0400 Message-ID: <5ee96a840903311522t10af5c64n53ab6f834ad475ff@mail.gmail.com> Subject: Re: MPC83xx console : no output after handover From: "Matthew L. Creech" To: Gary Thomas Content-Type: text/plain; charset=ISO-8859-1 Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Mar 31, 2009 at 5:26 PM, Gary Thomas wrote: > > The fact that you get the ttyS1 line printed is interesting. =A0At > this point, the kernel is switching from raw console I/O (only > suitable for bring-up messages) to the general serial driver > (interrupt driven, etc). =A0I'm curious about what the ttyS1 driver > is causing to break... > > A couple of things you could try: > =A0* Disable ttyS1 (take it out of your device tree) I tried taking ttyS1 out - the results are no different (other than the fact that "console handover" is now the last line that prints). My debug printk()s at the end of 8250_init() show up, which would seem to imply that ttyS0 was initialized correctly, so I'm not sure what else could be stomping on it. > =A0* Look at the console log when this happens. =A0Look in your system > =A0 =A0map for the symbol '__log_buf', e.g. > =A0 =A0 =A0 c031ca54 b __log_buf > =A0 =A0This will get stored at physical location '0x31ca54' and will > =A0 =A0often contain data that didn't get a chance to print, for example > =A0 =A0if you have stuck interrupts that prevent the console from working= . > =A0 =A0I'd just run it to this point and then examine the memory - either > =A0 =A0using a BDI if one is attached, or press RESET (I hope you have on= e!) > =A0 =A0and then look using your boot loader (uBoot, RedBoot, ...) > I think I can get my hands on a BDI tomorrow, so I'll give this a try then. Thanks for the reply --=20 Matthew L. Creech