Accessing serial port from TinyX

Greg KH greg at
Wed Jan 20 19:15:53 PST 2010

On Wed, Jan 20, 2010 at 05:53:43PM -0800, Ping Cheng wrote:
> This may not be the proper list to post a TinyX question.  But I see a
> few names in the source that are members of X.Org now. It should be a
> simple one for those who worked on the code.
> I am trying to let my driver communicate with a serial device
> (specifically, a Wacom serial device). This device works with my X.Org
> driver, which uses xf86SerialOpen and other related xf86 serial calls
> to communicate with the device. However, TinyX doesn't support those
> calls.  So, I have to "hack" into the original ones. The driver always
> fails at the tcsetattr() call with errno=25. Man page tells me:
> ENOTTY  Inapporatriate fd.
> What does this mean to me? How do I fix it? Or at least, how do I
> trace into the problem.

That means that you tried to do a tty ioctl on a non-tty device node.
Perhaps you are not opening the correct device?

good luck,

greg k-h

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