On Fri, Mar 28, 2014 at 02:19:23PM -0500, Rob Herring wrote: > On Fri, Mar 28, 2014 at 1:56 PM, Olof Johansson <o...@lixom.net> 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.
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