Re: Handling interrupts from userspace

Eric Lammerts (eric@scintilla.utwente.nl)
Sun, 1 Aug 1999 16:41:55 +0200 (CEST)


On Sun, 1 Aug 1999, Alan Cox wrote:

> > The interrupt handler can also disable the IRQ in the PIC. This
> > will prevent further interrupts after exiting the handler.
>
> It doesnt work for PCI for all cases

Just because PCI cards might be sharing interrupt lines or is there
any other reason?

> The card is on IRQ 9 you disable IRQ 9 you return to user space. IRQ 9 is shared with the
> disk. You do a disk I/O. Goodbye computer

It's true you can't do shared interrupts with my driver. But it'll
never try that: It requests the interrupt without SA_SHIRQ so your
scenario could never happen. You just get -EBUSY when you open the
device and the interrupt happens to be in use.

Eric

-- 
Eric Lammerts <eric@scintilla.utwente.nl>

"Don't you know there ain't no devil? There's just God when he's drunk." -- Tom Waits

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