Re: [PATCH] uio: User IRQ Mode

[Uwe Kleine-König]

Alan Cox wrote:
> On Wed, 02 Jul 2008 19:59:51 +0900
> Magnus Damm <magnus.damm@xxxxxxxxx> wrote:
> 
> > From: Uwe Kleine-König <Uwe.Kleine-Koenig@xxxxxxxx>
> >
> > This patch adds a "User IRQ Mode" to UIO. In this mode the user space driver
> > is responsible for acknowledging and re-enabling the interrupt.
> > Shared interrupts are not supported by this mode.
> 
> This doesn't work even for some non shared interrupts.
> 
> If I take a level triggered interrupt then the IRQ handler code must
> clear the IRQ before the line can be unmasked.
Note that the irq is disabled instead of acked.  So this should not be a
problem.  The userspace part then is responsible to ack (first) and
unmask the irq.

This mis-understanding might be a hint to improve the commit log ...

Best regards
Uwe

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Uwe Kleine-König, Software Engineer
Digi International GmbH Branch Breisach, Küferstrasse 8, 79206 Breisach, Germany
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