From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by bilbo.ozlabs.org (Postfix) with ESMTPS id 10235B8377 for ; Wed, 16 Sep 2009 07:44:18 +1000 (EST) Subject: Re: RFC: delete UART current-speed from 4xx DTS? From: Benjamin Herrenschmidt To: Josh Boyer In-Reply-To: <20090915153220.GG12372@zod.rchland.ibm.com> References: <20090915143135.GA7015@windriver.com> <20090915153220.GG12372@zod.rchland.ibm.com> Content-Type: text/plain Date: Wed, 16 Sep 2009 07:44:07 +1000 Message-Id: <1253051047.8375.232.camel@pasglop> Mime-Version: 1.0 Cc: Paul Gortmaker , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2009-09-15 at 11:32 -0400, Josh Boyer wrote: > On Tue, Sep 15, 2009 at 10:31:36AM -0400, Paul Gortmaker wrote: > >One of the guys here was getting a messed up console on a bamboo board > >(on linux boot), which he traced to the fact that the default dts has a > >9600 baudrate coded into it (board was running 115k2, not 9600). Either > >deleting the line, or replacing the 9600 with zero fixed the problem. > > Once booted, was there a valid current-speed property in /proc/device-tree > for the serial node? I'm curious if U-Boot created it, or if the kernel > just used whatever baud was present already. > > When I did the bamboo port a while ago, I recall having issues with either > a missing clock-frequency or current-speed (or both perhaps) and the bootloader > on the board was the original PIBS. It might have been an issue with PIBS > but I'm guessing the rest of the 4xx boards copied from either Ebony or > Bamboo in their ports and hence contain that property. I think I recently added code to legacy_serial probe the speed from the HW if the property is absent, which should help. Cheers, Ben.