console vs earlycon ?

[Masahiro Yamada]

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?



-- 
Best Regards
Masahiro Yamada