powerpc: dont include 8250 pre-setup if 8250 driver isn't enabled.

The legacy_serial code was setting things up based on the assumption
that the main 8250 driver would be loaded shortly after.  But some
randconfigs exposed an issue where early debug (UDB) UART support was
enabled, yet the core UART 8250 support was disabled.

In theory a person could care about _really_ early UART output for
early debug, but not care about generic console output via UART on
embedded devices, so fix things so it is a valid combination.

While this might seem like a pointless randconfig change, there are
some existing default configs that actually reflect the above setup.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

On Fri, Jan 20, 2012 at 10:50 PM, Paul Gortmaker
<paul.gortmaker@windriver.com> wrote:
> The legacy_serial code was setting things up based on the assumption
> that the main 8250 driver would be loaded shortly after.  But some
> randconfigs exposed an issue where early debug (UDB) UART support was
> enabled, yet the core UART 8250 support was disabled.

Hi Ben,

Can you mark this in patchworks as Superseded?  It is at:

http://patchwork.ozlabs.org/patch/137142/

You fixed it independently with this:

http://git.kernel.org/?p=linux/kernel/git/benh/powerpc.git;a=commit;h=3493c85366ba09c9d0972c919e7123367a39982a

Thanks,
Paul.


>
> In theory a person could care about _really_ early UART output for
> early debug, but not care about generic console output via UART on
> embedded devices, so fix things so it is a valid combination.
>
> While this might seem like a pointless randconfig change, there are
> some existing default configs that actually reflect the above setup.
>
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
>
> diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c
> index 3fea368..9a82a49 100644
> --- a/arch/powerpc/kernel/legacy_serial.c
> +++ b/arch/powerpc/kernel/legacy_serial.c
> @@ -413,6 +413,14 @@ void __init find_legacy_serial_ports(void)
>        DBG(" <- find_legacy_serial_port()\n");
>  }
>
> +/*
> + * In theory, one could have the early debugging enabled, but yet not care
> + * about 8250 after that, i.e. PPC_UDBG_16550=y but "SERIAL_8250 is not set".
> + * Mostly appears in randconfig builds, but some defconfigs have this.
> + */
> +
> +#ifdef CONFIG_SERIAL_8250
> +
>  static struct platform_device serial_device = {
>        .name   = "serial8250",
>        .id     = PLAT8250_DEV_PLATFORM,
> @@ -523,6 +531,7 @@ static int __init serial_dev_init(void)
>  }
>  device_initcall(serial_dev_init);
>
> +#endif /* CONFIG_SERIAL_8250 */
>
>  #ifdef CONFIG_SERIAL_8250_CONSOLE
>  /*
> --
> 1.7.7.2
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev

On Thu, 2012-02-02 at 12:56 -0500, Paul Gortmaker wrote:
> On Fri, Jan 20, 2012 at 10:50 PM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
> > The legacy_serial code was setting things up based on the assumption
> > that the main 8250 driver would be loaded shortly after.  But some
> > randconfigs exposed an issue where early debug (UDB) UART support was
> > enabled, yet the core UART 8250 support was disabled.
> 
> Hi Ben,
> 
> Can you mark this in patchworks as Superseded?  It is at:
> 
> http://patchwork.ozlabs.org/patch/137142/
> 
> You fixed it independently with this:
> 
> http://git.kernel.org/?p=linux/kernel/git/benh/powerpc.git;a=commit;h=3493c85366ba09c9d0972c919e7123367a39982a

No worries, thanks.

Cheers,
Ben.

> Thanks,
> Paul.
> 
> 
> >
> > In theory a person could care about _really_ early UART output for
> > early debug, but not care about generic console output via UART on
> > embedded devices, so fix things so it is a valid combination.
> >
> > While this might seem like a pointless randconfig change, there are
> > some existing default configs that actually reflect the above setup.
> >
> > Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> >
> > diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c
> > index 3fea368..9a82a49 100644
> > --- a/arch/powerpc/kernel/legacy_serial.c
> > +++ b/arch/powerpc/kernel/legacy_serial.c
> > @@ -413,6 +413,14 @@ void __init find_legacy_serial_ports(void)
> >        DBG(" <- find_legacy_serial_port()\n");
> >  }
> >
> > +/*
> > + * In theory, one could have the early debugging enabled, but yet not care
> > + * about 8250 after that, i.e. PPC_UDBG_16550=y but "SERIAL_8250 is not set".
> > + * Mostly appears in randconfig builds, but some defconfigs have this.
> > + */
> > +
> > +#ifdef CONFIG_SERIAL_8250
> > +
> >  static struct platform_device serial_device = {
> >        .name   = "serial8250",
> >        .id     = PLAT8250_DEV_PLATFORM,
> > @@ -523,6 +531,7 @@ static int __init serial_dev_init(void)
> >  }
> >  device_initcall(serial_dev_init);
> >
> > +#endif /* CONFIG_SERIAL_8250 */
> >
> >  #ifdef CONFIG_SERIAL_8250_CONSOLE
> >  /*
> > --
> > 1.7.7.2
> >
> > _______________________________________________
> > Linuxppc-dev mailing list
> > Linuxppc-dev@lists.ozlabs.org
> > https://lists.ozlabs.org/listinfo/linuxppc-dev