Re: [PATCH] serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250

From: Guenter Roeck <linux@roeck-us.net>
To: Florian Fainelli <f.fainelli@gmail.com>
Cc: arnd@arndb.de, Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250
Date: Mon, 19 Nov 2018 12:50:50 -0800	[thread overview]
Message-ID: <20181119205050.GA1933@roeck-us.net> (raw)
In-Reply-To: <ffff966c-d6ae-1487-5269-b86df0824d1c@gmail.com>

On Mon, Nov 19, 2018 at 10:44:30AM -0800, Florian Fainelli wrote:
> On 11/15/18 5:16 PM, Guenter Roeck wrote:
> > On Thu, Nov 15, 2018 at 11:48:20AM -0800, Florian Fainelli wrote:
> >>
> >> OK, would you mind testing this below? It seems to me that 8250_of.c is
> >> incompatible with arch/powerpc/kernel/legacy_serial.c and that is what
> >> is causing the issue here.
> >>
> >> diff --git a/drivers/tty/serial/8250/Kconfig
> >> b/drivers/tty/serial/8250/Kconfig
> >> index d7737dca0e48..21cb14cbd34a 100644
> >> --- a/drivers/tty/serial/8250/Kconfig
> >> +++ b/drivers/tty/serial/8250/Kconfig
> >> @@ -483,7 +483,7 @@ config SERIAL_8250_PXA
> >>
> >>  config SERIAL_OF_PLATFORM
> >>         tristate "Devicetree based probing for 8250 ports"
> >> -       depends on SERIAL_8250 && OF
> >> +       depends on SERIAL_8250 && OF && !(PPC && PPC_UDBG_16550)
> >>         default SERIAL_8250
> >>         help
> >>           This option is used for all 8250 compatible serial ports that
> > 
> > 44x/virtex5_defconfig has both PPC_UDBG_16550 and SERIAL_OF_PLATFORM enabled
> > and fails to boot (or display anything on the console) with this patch applied.
> 
> Thanks for trying, can you either share or provide a link to the mpc85xx
> and ml507 qemu command lines that you use? I spent a good chunk of my
> time trying to get a kernel to boot but has failed so far.
> 

Good to hear that this doesn't just happen to me ;-).

The scripts are all at https://github.com/groeck/linux-build-test/.
This includes root file systems. The one used below is at
https://github.com/groeck/linux-build-test/blob/master/rootfs/ppc/rootfs.cpio.gz

ml507:

qemu-system-ppc -kernel vmlinux -M virtex-ml507 -m 256 -no-reboot \
	-initrd rootfs.cpio -dtb arch/powerpc/boot/dts/virtex440-ml507.dtb \
	--append 'rdinit=/sbin/init panic=-1 mem=256M console=ttyS0' \
	-monitor none -nographic

mpc85xx:

qemu-system-ppc -kernel arch/powerpc/boot/uImage -M mpc8544ds -m 256 \
	-no-reboot -initrd rootfs.cpio \
	--append 'rdinit=/sbin/init panic=-1 mem=256M console=ttyS0' \
	-monitor none -nographic

Hope this helps,
Guenter