Re: [PATCH v12 1/1] serial: core: Start managing serial controllers to enable runtime PM

[Tony Lindgren]

* Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> [230601 14:16]:
> On 01.06.2023 15:20, Tony Lindgren wrote:
> > * Tony Lindgren <tony@xxxxxxxxxxx> [230601 11:12]:
> >> * Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> [230601 11:00]:
> >>> This patch landed in today's linux next-20230601 as commit 84a9582fd203
> >>> ("serial: core: Start managing serial controllers to enable runtime
> >>> PM"). Unfortunately it breaks booting some of my test boards. This can
> >>> be easily reproduced with QEMU and ARM64 virt machine. The last message
> >>> I see in the log is:
> >>>
> >>> [    3.084743] Run /sbin/init as init process
> >> OK thanks for the report. I wonder if this issue is specific to ttyAM
> >> serial port devices somehow?
> > Looks like the problem happens with serial port drivers that use
> > arch_initcall():
> >
> > $ git grep arch_initcall drivers/tty/serial/
> > drivers/tty/serial/amba-pl011.c:arch_initcall(pl011_init);
> > drivers/tty/serial/mps2-uart.c:arch_initcall(mps2_uart_init);
> > drivers/tty/serial/mvebu-uart.c:arch_initcall(mvebu_uart_init);
> > drivers/tty/serial/pic32_uart.c:arch_initcall(pic32_uart_init);
> > drivers/tty/serial/serial_base_bus.c:arch_initcall(serial_base_init);
> > drivers/tty/serial/xilinx_uartps.c:arch_initcall(cdns_uart_init);
> >
> > We have serial_base_bus use module_init() so the serial core controller
> > and port device associated with the physical serial port are not probed.
> >
> > The patch below should fix the problem you're seeing, care to test and
> > if it works I'll post a proper fix?
> 
> Right, this fixes my issue. Feel free to add:
> 
> Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>

OK great just posted it with your Reported-by before seeing this, I added
returning an error too so maybe reply to the posted patch with your
Tested-by assuming it's still OK for you.

For reference if other folks are hitting this, the fix is at [0] below.

Regards,

Tony


[0] https://lore.kernel.org/linux-serial/20230601141445.11321-1-tony@xxxxxxxxxxx/T/#u