[PATCH] usb: Make what it takes for "usbkbd" to work in "stdin" clear

[Marek Vasut]

On 1/19/25 7:50 PM, Dragan Simic wrote:
> Selecting the CONFIG_SYS_CONSOLE_ENV_OVERWRITE option actually prevents the
> CONFIG_USB_KEYBOARD option from working as expected, i.e. USB keyboards end
> up not working as console inputs when "usbkbd" is properly specified as part
> of the value of the "stdin" environment variable.  Describe this clearly in
> the two relevant Kconfig files, to prevent any possible confusion.
> 
> In more detail, the console_init_r() function ends up overwriting the "stdin"
> environment variable so it contains only the devices available at that point
> (which doesn't include "usbkbd"), while the "usb start" operation is performed
> much later, at which point the probe_usb_keyboard() function cannot assign any
> discovered USB keyboards to the console because "usbkbd" is no longer present
> in the "stdin" environment variable.
Wouldn't it be better to patch console_init_r() , check if "stdin" 
variable contains 'usbkbd' and if so, start USB and register the 
keyboard as stdin device at this point ? This is called after 
relocation, so starting USB should be OK to do here. The behavior should 
then be less confusing to users too.