[PATCH v2 3/7] tty/serial: convert 8250 to generic earlycon

[Rob Herring]

On Mon, Jun 9, 2014 at 5:25 PM, Tony Luck <tony.luck at gmail.com> wrote:
> On Sat, May 3, 2014 at 3:16 PM, Greg Kroah-Hartman
> <gregkh at linuxfoundation.org> wrote:
>>> > >>  drivers/tty/serial/8250/8250_early.c | 138 ++++-------------------------------
>>> > >>  drivers/tty/serial/8250/Kconfig      |   1 +
>>> > >>  2 files changed, 16 insertions(+), 123 deletions(-)
>>> > >
>>> > > Hi Greg, Rob
>>> > >
>>> > > This one in tty-next breaks booting: "console=uart8250,io,0x3f8,115200".
>>> > > No early console and regular console anymore.
>>> > >
>>> > > It should produce "early con and regular con".
>>> >
>>> > This is what I get for running checkpatch and converting
>>> > simple_strtoul to kstrto* which are not so equivalent. kstrto* will
>>> > not convert things such as 115200n8 to a number.
>>> >
>>> > Greg, Do you want a fix or for me to respin the series? The fix looks like this:
>>>
>>> As this is in my tree now (right?), I need a fix to apply to it.
>>
>> Nevermind, you already sent it...
>
> Linus' tree (HEAD=963649d735c8) is spitting out all sorts of garbage
> on the serial console - as if the baud rate is being periodically set
> to something weird, and then back to 112500.  I see over a dozen
> blocks of junk interspersed with good output.

Is there any correlation of the garbage to printks of console enabled messages?

>
> This in on ia64 with "console=uart,io,0x3f8" on the command line.

Does "console=ttyS0,115200" or "console=uart,io,0x3f8,115200" work?

You will need this fix for the 2nd one to work:

commit e26f1db9b8d74617519e50b41749900d0a257406
Author: Rob Herring <robh at kernel.org>
Date:   Wed Apr 30 19:48:29 2014 -0500

    tty/serial: fix generic earlycon option parsing

Rob

>
> git bisect pointed me here:
>
> d2fd6810a823bcde1ee232668f5689837aafa772 is first bad commit
> commit d2fd6810a823bcde1ee232668f5689837aafa772
> Author: Rob Herring <robh at kernel.org>
> Date:   Fri Apr 18 17:19:56 2014 -0500
>
>     tty/serial: convert 8250 to generic earlycon
>
> -Tony