Re: [PATCH] Use tty_schedule in VT code.

Linus Torvalds
2007-07-18T20:09:17Z

On Wed, 18 Jul 2007, Paul Fulghum wrote:
>
> It might be safest to drop this portion so you can get the
> obvious part of the patch accepted (consolidating
> the redundant xxx_schedule_flip functions).

But wasn't the whole _point_ that con_schedule_flip() potentially gets
called from interrupt context, and thus that part is wrong. It's why
con_schedule_flip() was different from tty_schedule_flip() to begin with,
no?

If a tty driver has marked itself low-latency, it's still wrong to do the
flush_to_ldisc() from interrupt context if a console event happens in
interrupt context.

I thought that was the whole *point* of the difference between
"tty_schedule_flip()" and "con_schedule_flip()", as far as I know. The
"con_schedule_flip()" can be called from any context (console messages),
while "tty_schedule_flip()" is only called from well-behaved tty layer.

But I really don't know. I used to be involved with the tty layer, these
days I'd rather avoid it. This "simple" patch seems to be anything but,
and I'd like somebody to just make sure that all the issues are taken care
of.

Alan?

Linus