From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hurley Subject: Re: earlycon: no match? Date: Thu, 07 May 2015 13:22:11 -0400 Message-ID: <554B9F43.6000702@hurleysoftware.com> References: <20150503211054.GR15254@pengutronix.de> <55477BC1.6000805@hurleysoftware.com> <20150504194229.GR15254@pengutronix.de> <5547D4DB.8060300@hurleysoftware.com> <20150504205241.GT15254@pengutronix.de> <5547E447.9020604@hurleysoftware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: "Maciej W. Rozycki" Cc: Robert Schwebel , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de List-Id: linux-serial@vger.kernel.org On 05/07/2015 01:09 PM, Maciej W. Rozycki wrote: > On Mon, 4 May 2015, Peter Hurley wrote: > >>>> Since 2007, 'console=' is a early param synonym for 'earlycon='; IOW, >>>> the message is new but not the behavior. >>> >>> "console=" had nothing to do with early param before. >> >> *Yes, it has* since the commit I referenced in the previous email and >> the email before that when I noted that 'console=' and 'earlycon=' are >> synonyms if CONFIG_SERIAL_EARLYCON=y, and it has been that way since >> 2007. >> >> The only thing that has changed is that I added a diagnostic; _to repeat_, >> the earlycon matching code has always run in this case, only the >> diagnostic is new. > > What's the point of having two parameters as synonyms whose syntax is not > compatible to each other in the general case? I'd expect the following > cases to be handled: > > 1. Regular console only (no early console requested) => `console=foo...'. > > 2. Both early and regular console => `earlycon=blah... console=foo...'. > > 3. Early console handing over to regular console => `earlycon=blah...'. 4. Early console only => `earlycon=blah...' How to distinguish between 3 & 4? > Why do you want to support `console=blah...' too (a question to be asked > back in 2007, but better late than never)? Command line is considered to be userspace, so it doesn't really matter what I think about whether console= should have been overloaded like that. The fact is, it was. > If you do need to support such aliasing, then I suggest that you complain > about no early console match only if `earlycon=blah...' has been truly > used and avoid the warning where `console=blah...' has been used instead > (a warning about the latter can be issued where no regular console match > happened). I'm tearing it out; I'd prefer to go back to the old way where you don't know why your earlycon didn't start, and I don't get emails complaining about logs. Regards, Peter Hurley