[U-Boot] [PATCH] ls102xa: dm: serial: Disable CONFIG_DM_STDIO for LCD/HDMI display

[Huan Wang]

Hi, Simon,

> On 1 March 2016 at 02:06, Alison Wang <b18965 at freescale.com> wrote:
> > When LCD/HDMI is connected to LS1021ATWR or LS1021AQDS, the console
> > output should be shown on the monitor.
> >
> > If CONFIG_DM_SERIAL and CONFIG_DM_STDIO are both enabled, serial
> > device is registered and added to the stdio list in serial-uclass.c.
> > Then, vga device will be registered and added to the stdio list in
> cfb_console.c.
> > So serial device is at the head of the stdio list and will be chosen
> > as the input and output device in console_init_r(). It will cause the
> > console output can't be shown on the monitor.
> >
> > If CONFIG_DM_STDIO is disabled when using CONFIG_DM_SERIAL. First, vga
> > device is registered and added to the stdio list in cfb_console.c.
> > Then serial device will be registered and added to the stdio list in
> > drv_system_init(). So vga device is at the head of the stdio list and
> > will be chosen as the input and output device in console_init_r(). The
> > console output will be shown on the monitor.
> >
> > The patch is to disabled CONFIG_DM_STDIO for LCD/HDMI display.
> >
> > Signed-off-by: Alison Wang <alison.wang at nxp.com>
> 
> Have you tried enabling CONFIG_CONSOLE_MUX?
> 
[Alison Wang] Thanks for your advice. I got your idea, and tried to
enable CONFIG_CONSOLE_MUX and CONFIG_SYS_CONSOLE_IS_IN_ENV. Then after
setting "stdout=serial,vga", the console output is both shown on monitor
and serial terminal.

This patch is not a good way to fix the problem, please abandon it. Enabling
CONFIG_SYS_CONSOLE_IS_IN_ENV is the best way to fix the problem, and Enabling
CONFIG_CONSOLE_MUX could be used to shown the console output on multiple
devices simultaneously.


Best Regards,
Alison Wang