Messages in this thread | | | Date | Wed, 4 Jun 2008 09:05:43 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 1/1] UIO: Add a write() function to enable/disable interrupts |
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On Wed, 4 Jun 2008, Uwe Kleine-König wrote: > Hello Hans-Jürgen, > > > Sometimes it is necessary to enable/disable the interrupt of a UIO device > > from the userspace part of the driver. With this patch, the UIO kernel driver > > can implement an "irqcontrol()" function that does this. Userspace can write > > an s32 value to /dev/uioX (usually 0 or 1 to turn the irq off or on). The > > UIO core will then call the driver's irqcontrol function. > IMHO it would make sense to demand that irqcontrol() is idempotent and > then call irqcontrol(ON) before blocking in read and poll.
We thought about that, but it is racy. Also explicit control is way better than automagic hackery.
Thanks, tglx
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