[PATCH] serial: mvebu-uart: fix tx lost characters

gregkh at linuxfoundation.org gregkh at linuxfoundation.org
Thu Mar 15 09:55:16 PDT 2018


On Tue, Mar 06, 2018 at 03:47:03PM +0000, Gabriel Matni wrote:
> From: Gabriel Matni <gabriel.matni at exfo.com>
> 
> Fixes missing characters on kernel console at low baud rates (i.e.9600).
> The driver should poll TX_RDY or TX_FIFO_EMP instead of TX_EMP to ensure
> that the transmitter holding register (THR) is ready to receive a new byte.
> 
> TX_EMP tells us when it is possible to send a break sequence via
> SND_BRK_SEQ. While this also indicates that both the THR and the TSR are
> empty, it does not guarantee that a new byte can be written just yet.
> 
> Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port")
> Reviewed-by: Miquel Raynal <miquel.raynal at bootlin.com> 
> Acked-by: Gregory CLEMENT <gregory.clement at bootlin.com>  
> Signed-off-by: Gabriel Matni <gabriel.matni at exfo.com> 
> ---
> drivers/tty/serial/mvebu-uart.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
> index a100e98259d7..f0df0640208e 100644
> --- a/drivers/tty/serial/mvebu-uart.c
> +++ b/drivers/tty/serial/mvebu-uart.c
> @@ -618,7 +618,7 @@ static void wait_for_xmitr(struct uart_port *port)
>    u32 val;
> 
>    readl_poll_timeout_atomic(port->membase + UART_STAT, val,
> -             (val & STAT_TX_EMP), 1, 10000);
> +             (val & STAT_TX_RDY(port)), 1, 10000);
> }
> 
> static void mvebu_uart_console_putchar(struct uart_port *port, int ch)
> --
> 2.7.4

Patch is corrupted and can not be applied :(

Please fix up and resend.

Also be sure to cc: the linux-serial mailing list,
scripts/get_maintainer.pl is your friend...

thanks,

greg k-h



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