[PATCH 3/6] serial: meson: remove unneeded variable assignment in meson_serial_port_write

[afaerber@suse.de (Andreas Färber)]

Am 17.04.2017 um 17:27 schrieb Neil Armstrong:
> On 04/17/2017 03:58 PM, Ben Dooks wrote:
>> On 16/04/17 21:13, Heiner Kallweit wrote:
>>> AML_UART_TX_EN is set in meson_uart_startup and there's no place in
>>> the driver where it gets cleared. Therefore we don't have to set it
>>> here.
>>
>> I think this is a leftover of the patches I did when trying to fix
>> the UART driver when using debian/systemd and having strange console
>> problems.
>>
>> The only comment is it might be worth leaving this in as it isn't
>> a high cost to the driver and it is possible someone might accidentally
>> clear it later.
>>
>>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
>>> ---
>>>  drivers/tty/serial/meson_uart.c | 1 -
>>>  1 file changed, 1 deletion(-)
>>>
>>> diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
>>> index 22857f1e..714b29ad 100644
>>> --- a/drivers/tty/serial/meson_uart.c
>>> +++ b/drivers/tty/serial/meson_uart.c
>>> @@ -497,7 +497,6 @@ static void meson_serial_port_write(struct uart_port *port, const char *s,
>>>      }
>>>
>>>      val = readl(port->membase + AML_UART_CONTROL);
>>> -    val |= AML_UART_TX_EN;
>>>      tmp = val & ~(AML_UART_TX_INT_EN | AML_UART_RX_INT_EN);
>>>      writel(tmp, port->membase + AML_UART_CONTROL);
>>>
>>>
>>
>>
> 
> I'm ok to remove it, having it in uart_startup is enough.
> 
> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>

Have you checked the earlycon code paths? That does not run through the
standard setup function, so it is dependent on what the firmware set
last. I believe I am calling into this function through some wrapper.

Since we're writing the register anyway, it shouldn't hurt to leave this in.

Regards,
Andreas

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