[PATCH] serial: imx: Disable new features of autobaud detection

[Eric Nelson]

On 05/14/2014 11:55 AM, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam at freescale.com>
>
> Bit 7 of UCR3 is described in the i.MX reference manuals (with the exception
> of i.MX1) as follows:
>
> ADNIMP: Autobaud Detection Not Improved-. Disables new features of
> 	autobaud detection (See Baud Rate Automatic Detection
> 	Protocol, for more details).
>
> 	0 Autobaud detection new features selected
> 	1 Keep old autobaud detection mechanism
>
> The "new features" mechanism occasionally cause the receiver to get out of sync
> and continuously produce received characters of '\xff'.
>
> In order to reproduce the problem:
>
> $ stty -F /dev/ttymxc0 19200
>
> - Change the terminal baudrate to 19200
>
> - Type in the console and it should look good
>
> - Change the terminal baudrate back to 115200
>
> - Type 'b' in the console, then a stream of garbage characters is seen.
>
> Also rename the bit definition as per the reference manual.
>
> Tested on mx6q, mx6dl, mx6solo and mx53.
>
> Based on a patch from Eric Nelson for U-boot.
>
> Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
> ---
>   drivers/tty/serial/imx.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>

Tested-by: Eric Nelson <eric.nelson at boundarydevices.com>