VGA arbitration: API proposal

[Jon Smirl]

On Sat, 05 Mar 2005 16:18:01 +1100, Benjamin Herrenschmidt
<benh at kernel.crashing.org> wrote:
> Wether we are talking with kernel consoles or user consoles, the problem
> of VGA access remains the same. Let's be constructive now, please
> comment on my proposal, and if you have nothing to object, let's try to
> make it a reality.

There is definitely a demand for systems with multiple videos card
allowing multiple simultaneous logins. The ruby project implements
this with a current kernel diff of 13,000 lines. There are also two
(maybe more) commercial companies selling systems based on this. So if
simultaneous users are to be addressed VGAcon has to be looked at. As
Alan points out it may be difficult to make multiple in-kernel VGAcons
work. For example VGAcon can do printk at interrupt time.

What about legacy code that doesn't contain vga_get/vga_put. brackets?
You can't just do this on VT switch in the simultaneous user case.

-- 
Jon Smirl
jonsmirl at gmail.com