From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [RFC PATCH] tty: serial: Add 8250-core based omap driver Date: Thu, 3 Jul 2014 00:34:11 -0700 Message-ID: <20140703073411.GX28884@atomide.com> References: <1404316809-20637-1-git-send-email-bigeasy@linutronix.de> <20140702160932.GF5541@saruman.home> <20140702190944.GA567@drone.musicnaut.iki.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Robert Nelson Cc: Aaro Koskinen , Felipe Balbi , Sebastian Andrzej Siewior , linux kernel , linux-serial@vger.kernel.org, Linux OMAP Mailing List , Linux ARM Kernel Mailing List List-Id: linux-omap@vger.kernel.org * Robert Nelson [140702 12:27]: > On Wed, Jul 2, 2014 at 2:09 PM, Aaro Koskinen wrote: > > Hi, > > > > On Wed, Jul 02, 2014 at 11:09:32AM -0500, Felipe Balbi wrote: > >> > It has been only tested as console UART. > >> > The tty name is ttyS based instead of ttyO. How big is the pain here, > >> > what could be the easiest way to provide compatibility? > >> > >> have been considering that myself for months. You could pass an optional > >> argument to serial8250_register_8250_port() but that only solves part of > >> the problem :-( Some kind of compability layer sure would be nice. > > When ttyS -> ttyO change was done on OMAP, compatibility was not an issue. > > Why should we care about it now? > > It would be a good opportunity to force everyone to update their bootloader. ;) > > Besides the BeagleBoard forum is quiet now, no one is complaining > about that old (ttyS -> ttyO) transition anymore.. How about a Kconfig option to provide ttyO by default? The not even do that if kernel has cmdline option nottyomap. > I'll just end up carrying a patch like, to support bb.org users over > the transition.. > > https://github.com/RobertCNelson/stable-kernel/blob/v3.7.x/patches/omap_beagle/0004-zeroMAP-Open-your-eyes.patch Heh. Just to summarize the reason ttyO needs to be a separate name and device entry from ttyS is because we also have external 8250 devices on GPMC and hotplug busses. Regards, Tony