On Wednesday 21 October 2015 17:21:07 Masahiro Yamada wrote: > Hi. > > > > > I think there are three places where console could be enabled. > > [1] earlycon > > Each driver entry is declared with > EARLYCON_DECLARE() or OF_EARLYCON_DECLARE() > > > > [2] console_init() > > Each entry is declared with console_initcall() > > > > [3] when driver is probed > The console is usually enabled at this point > unless some special treatment is done. > > > > > My question is about [2]. > > I am using 8250-ish UART device. > > > I noticed univ8250_console_match() and univ8250_console_setup() > always fail at the point of [2] unless early_serial_setup() has been > called in advance; > however, it looks like early_serial_setup() is only used for old platforms. > > So, console cannot be enabled at [2] for modern platforms. > > > My questions are: > > - Given that earlycon can be now available for major architectures such ARM, > [2] will be deprecated at some point in the future? > > - I am implementing earlycon for my own UART driver. > Is it meaningless to implement console_initcall() as well as earlycon? I would still do both. We don't enable earlycon by default at the moment, and I'd say things should remain working with just console_initcall(). How closely related to 8250 is your hardware? If it's not all that different, you should probably reuse the existing driver. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
