[PATCH] serial/core: Initialize the console pm state

[Geert Uytterhoeven]

On Wed, Oct 1, 2014 at 7:27 PM, Kevin Hilman <khilman at kernel.org> wrote:
> On Sun, Sep 21, 2014 at 11:30 PM, Sudhir Sreedharan
> <ssreedharan at mvista.com> wrote:
>> For console devices having UART_CAP_SLEEP capability, the uart_pm_state has
>> to be initialized to UART_PM_STATE_ON. Otherwise the LCR regiser values
>> are reinitialized when uart_change_pm is called from uart_configure_port.
>>
>> Signed-off-by: Sudhir Sreedharan <ssreedharan at mvista.com>
>
> Multiple boot failures on ARM[1] were bisected down to this patch.
>
> How was this patch tested, and on which platforms?
>
> Also, the changelog states that this should be done only for
> UART_CAP_SLEEP, but the patch does it for every UART.
>
> Greg, I suggest this patch be dropped from tty-next until it has been
> better described and tested.
>
> Kevin
>
> [1] http://lists.linaro.org/pipermail/kernel-build-reports/2014-October/005550.html

Perhaps it should call "uart_change_pm(state, UART_PM_STATE_ON)"
instead, so the driver's .pm() method is called?

UART_CAP_SLEEP seems to be an 8250-only flag.

BTW, this was the first commit I reverted when I had an issue with a serial
console yesterday, but it didn't seem to have any influence (for me).

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds