On Fri, 28 Mar 2014 13:58:36 -0700, Christoffer Dall <christoffer.dall@xxxxxxxxxx> wrote: > On Fri, Mar 28, 2014 at 02:19:23PM -0500, Rob Herring wrote: > > On Fri, Mar 28, 2014 at 1:56 PM, Olof Johansson <olof@xxxxxxxxx> 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. For real hardware using a serial console, I think we want to fix this. Right my embedded rootfs (buildroot) isn't portable between machines only because the getty device gets hard coded. /proc/cmdline doesn't really solve the problem since it doesn't handle non-cmdline selected consoles. However, /proc/consoles should do the job. g. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
