Re: Is it useful to support user level drivers

Matthias Urlichs
2001-06-21T14:06:30Z

At 14:28 +0100 2001-06-21, Alan Cox wrote:
>No. The IRQ might be shared, and you get a slight problem if you just disabled
>an IRQ needed to make progress for user space to handle the IRQ

Two choices:

- Disallow shared interrupts for usermode drivers.

- Make the 'generic interrupt handler device driver' configurable
and/or module-extensible. You only need three entry points
("Interrupt set?"/"Enable interrupts"/"Disable interrupts"), which is
reasonably simple to get right.
--
Matthias Urlichs