[PATCH 06/11] tty: serial: Add Actions Semi Owl UART earlycon

Arnd Bergmann
2017-02-20T15:17:06Z

On Mon, Feb 20, 2017 at 2:40 PM, Andreas F?rber <afaerber@suse.de> wrote:
> Am 16.02.2017 um 14:41 schrieb Arnd Bergmann:
>> On Wednesday, February 15, 2017 5:55:23 PM CET Andreas F?rber wrote:
>>> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
>>> index 6117ac8..9d4213c 100644
>>> --- a/drivers/tty/serial/Kconfig
>>> +++ b/drivers/tty/serial/Kconfig
>>> @@ -1677,6 +1677,25 @@ config SERIAL_MVEBU_CONSOLE
>>> and warnings and which allows logins in single user mode)
>>> Otherwise, say 'N'.
>>>
>>> +config SERIAL_OWL
>>> + bool "Actions Semi Owl serial port support"
>>> + depends on ARCH_OWL || COMPILE_TEST
>>> + select SERIAL_CORE
>>> + help
>>> + This driver is for Actions Semi S500/S900 SoC's UART.
>>> + Say 'Y' here if you wish to use the on-board serial port.
>>> + Otherwise, say 'N'.
>>> +
>>>
>>
>> This could maybe use a word of information about how there isn't
>> actually a uart driver in this series, only an earlycon driver.
>
> Yeah, I have added a sentence to the other one. Maybe also add a select?

I generally only use 'select' to avoid build failures, not to save the user
the time to make a choice.

>> Do you plan to add the actual tty driver soon? If not, maybe
>> only add one Kconfig symbol for the earlycon support.
>
> So, I completed the driver the weekend and can see the full console
> output, but there are still output glitches, possible locking issues up
> to RCU stalls and soft lockups, and only stubbed out baudrate support.
>
> Therefore I would rather keep the full driver as follow-up RFC in v2,
> unless I get it fixed during Hackweek. In the earlycon I am confident,
> and the only Kconfig change then is to switch from bool to tristate and
> to drop the newly added sentence again.

Ok, sounds good.

Arnd