[OE-core] Yocto Bug#10456 discuss

[Bruce Ashfield]

On 2017-02-24 5:33 AM, Dengke Du wrote:
> Hi Jussi and bruce
>
> Yocto Bug#10456: X can not launch on qemumips64
>
> I find the kernel 4.4 is ok, and on the latest 4.9 is ok, but on kernel
> 4.8 is failed.
>
> This is because this commit in linux-yocto-4.8:
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> commit d03516df837587368fc6e75591f6329c072b9eb5
> Author: Matthew Leach <matthew.leach at codethink.co.uk>
> Date:   Tue Jun 21 16:19:49 2016 +0100
>
>     tty: serial: 8250: add CON_CONSDEV to flags
>
>     When using the 8250 as a boot console and the main console results in
>     messages being printed twice.  The console framework will only
>     unregister boot consoles if a new console is registered with the
>     CON_CONSDEV flag set.
>
>     Set this flag for the univ8250 console to prevent double-registration.
>
>     Signed-off-by: Matthew Leach <matthew.leach at codethink.co.uk>
>     Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
>
> diff --git a/drivers/tty/serial/8250/8250_core.c
> b/drivers/tty/serial/8250/8250_core.c
> index fa823a5..dcf43f6 100644
> --- a/drivers/tty/serial/8250/8250_core.c
> +++ b/drivers/tty/serial/8250/8250_core.c
> @@ -675,7 +675,7 @@ static struct console univ8250_console = {
>         .device         = uart_console_device,
>         .setup          = univ8250_console_setup,
>         .match          = univ8250_console_match,
> -       .flags          = CON_PRINTBUFFER | CON_ANYTIME,
> +       .flags          = CON_PRINTBUFFER | CON_ANYTIME | CON_CONSDEV,
>         .index          = -1,
>         .data           = &serial8250_reg,
>  };
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> The 4.9 has been reverted it, so backport that reverted patch can fix
> this bug, but I don't know why this related to qemumips64?

Looks like the console is interfering with X claiming a VT for
startup.

But I wouldn't worry about the root cause all that much, if you've
bisected it, and it has been reverted already in newer kernels .. that
should be enough evidence for anyone.

Bruce

>
> Thanks
>
> Dengke
>