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Re: sys_ioctl under amd64 (Was: AMD64 patch for flavio's fglrx debs)

On Apr 10, 2005 7:47 PM, Cyril Chaboisseau <cyril.chaboisseau@free.fr> wrote:
> do you think it's the "console switching" or the XFree86 drivers ?

I had a discussion with Lutz Donnerhacke (iirc) about that a few years
ago. He said (and I do agree), that the console switching in Linux is
broken by design. You may notice that it is pretty unique even in the
UNIX world, so maybe everybody else figured it is to difficult.

The problem is that you have one resource (your graphics card), which
is handled by several drivers, that you can switch around with C-A-Fn.
Getting this right is very complicated, it requires that all drivers
properly release and restore the state of the resource and always
share up to date information about their use of the resource. It is so
complicated that is usually only works to 99%.

The correct solution would be to have one driver that manages the
hardware, and to switch the consoles on top of this driver.
Unfortunately, that requires the driver to work before you can see any
output. And I do not know a way to switch between different graphical
users in one X11 server.

To keep it short: the driver is broken, but it is broken because the
design is too complex.

Why did ATI stop to release the specs? Back in the old days, ATI was
the best bet for Linux after Matrox, but now I am not so sure any


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