Framebuffer overwritten with text

Framebuffer overwritten with text

Post by jeffc.. » Sat, 24 Jun 2006 06:59:12



My company is developing a product using embedded Linux.  I wrote a
simple framebuffer device driver for our graphics chip, and everything
works well until I plug in a USB keyboard.  The characters typed on the
keyboard are echoed to the framebuffer device, overwriting our display.
 We are not running a getty or shell attached to the framebuffer, but I
haven't been able to figure out how to suppress the output of the USB
keyboard.  We are running Linux 2.4.25 with DenX's RTAI patch on
powerpc.

Thanks,
Jeff Crow

 
 
 

Framebuffer overwritten with text

Post by chuckca » Sat, 24 Jun 2006 10:11:37




Quote:> My company is developing a product using embedded Linux.  I wrote a
> simple framebuffer device driver for our graphics chip, and everything
> works well until I plug in a USB keyboard.  The characters typed on
> the keyboard are echoed to the framebuffer device, overwriting our
> display.
>  We are not running a getty or shell attached to the framebuffer, but
>  I
> haven't been able to figure out how to suppress the output of the USB
> keyboard.  We are running Linux 2.4.25 with DenX's RTAI patch on
> powerpc.

> Thanks,
> Jeff Crow

A simple solution: use a ps/2 or standard keyboard and see if you still
have the same problem. If not, all the better: usb hogs the bus anyways.

--
(setq (chuck nil)  car(chuck) )

 
 
 

Framebuffer overwritten with text

Post by xask » Sat, 24 Jun 2006 16:25:23


hi there,

i am quite a beginner at these things but i think this page might help
you --
http://gentoo-wiki.com/HOWTO_fbsplash#Kernel_Options
scroll down a bit from this point and it will mention a "Warning about
kernel writing its output on the frame buffer", i think this will be
helpful,

bye!


> My company is developing a product using embedded Linux.  I wrote a
> simple framebuffer device driver for our graphics chip, and everything
> works well until I plug in a USB keyboard.  The characters typed on the
> keyboard are echoed to the framebuffer device, overwriting our display.
>  We are not running a getty or shell attached to the framebuffer, but I
> haven't been able to figure out how to suppress the output of the USB
> keyboard.  We are running Linux 2.4.25 with DenX's RTAI patch on
> powerpc.

> Thanks,
> Jeff Crow