From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [RFC 0/5] of: Automatic console registration cleanups Date: Fri, 28 Mar 2014 13:58:36 -0700 Message-ID: <20140328205836.GN25519@cbox> References: <1396022885-6102-1-git-send-email-grant.likely@linaro.org> <20140328185653.GB26433@quad.lixom.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring Cc: Olof Johansson , Grant Likely , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Benjamin Herrenschmidt , Rob Herring List-Id: devicetree@vger.kernel.org On Fri, Mar 28, 2014 at 02:19:23PM -0500, Rob Herring wrote: > On Fri, Mar 28, 2014 at 1:56 PM, Olof Johansson wrote: > > On Fri, Mar 28, 2014 at 09:08:00AM -0700, Grant Likely wrote: > >> Hi all, > >> > >> This is a series that I've been playing with over the last few days to > >> clean up the selection of default console devices when using the device > >> tree. The device tree defines a way of specifying the console by using a > >> "stdout-path" property in the /chosen node, but very few drivers > >> actually attempt to use that data, and so for most platforms there needs > >> to be a "console=" line in the command line if a serial port is intended > >> to be used as the console. > >> > >> With this series, if there is a /chosen/stdout-path property, and if > >> that property points to a serial port node, then when the serial driver > >> registers the port, the core uart_add_one_port() function will notice > >> and if no console= argument was provided then add it as a preferred > >> console. > >> > >> I've not tested this very extensively yet, but I want to get some > >> feedback before I go further. > >> > >> The one downside with this approach is that it doesn't do anything for > >> early console setup. That still needs to be added on a per-driver basis, > >> but at least it shouldn't conflict with this approach. > > I'm working on the early aspect. I've got things working with either > command line (which I sent out recently) and with parsing the FDT > (which I haven't sent out yet). > > > Looks sane to me (as discussed in person). I gave it a run on PWRficient with > > and without console= line (8250-based uart), and it behaved as expected. > > > > A couple of nits on the series, replied to two of the patches. > > > > I'll give it a run through the board farm here too, but I'll keep console= > > bootargs there for those boots at this time, too much to change to take it out > > everywhere. :-) > > It would be good to know if removing console= causes userspace any > issues. For example, if getty's were setup based on console params. I > know ubuntu does some detection of serial ports, but I don't recall > what it looks at. Hopefully it's just checking /dev nodes. > In Ubuntu, recent versions at least, it's all just hardcoded in /etc/init/*.conf files. The Linaro OE FS does check /proc/cmdline for console= in there - not sure if we care, or at least we can have it fixed quickly. -Christoffer -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html