[U-Boot] [PATCH] imx: serial: Wait for ongoing transmission to finish before serial reset

[Simon Glass]

Hi Lukasz,

On 3 October 2017 at 03:16, Lukasz Majewski <lukma at denx.de> wrote:
> It may happen that the MXC serial IP block is performing some ongoing
> transmission (started at e.g. board_init()) when the "initr_serial" is
> called.
>
> As a result the serial port IP block is reset, so transmitted data is
> corrupted:
>
> I2C:   ready
> DRAM:  1 GiB
> jSS('HH��SL_SDHC: 04 rev 0x0
>
> This patch prevents from this situation, by waiting for transmission
> complete bit set (UART Status Register 2 (UARTx_USR2), bit TXDC):
>
> I2C:   ready
> DRAM:  1 GiB
> ID:    unit type 0x4 rev 0x0
>
> Signed-off-by: Lukasz Majewski <lukma at denx.de>
> ---
>
>  drivers/serial/serial_mxc.c | 7 +++++++
>  1 file changed, 7 insertions(+)

Is it possible to use driver model to do this in a generic way for all
serial drivers? The pending() method allows you to check if there are
any characters in the output FIFO.

Regards,
Simon