Messages in this thread | | | Date | Fri, 12 Oct 2007 16:23:15 -0400 | From | "Dmitry Torokhov" <> | Subject | Re: [PATCH try #2] Input/Joystick Driver: add support AD7142 joystick driver |
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On 10/12/07, Ahmed S. Darwish <darwish.07@gmail.com> wrote: > On Fri, Oct 12, 2007 at 01:29:31PM -0400, Dmitry Torokhov wrote: > > > > > Isn't disabling device interrupts from the begining of the ISR "ad7142_interrupt" > > > till the kthread "ad7142_thread" got waked-up and scheduled a long time, > > > espicially if there's a high load on the userspace side ? > > > > > > > It is OK - you disable a specific interrupt line preventing it from > > raising any more IRQs until current one is serviced. > > Won't this affect system responsiveness if the IRQ line was shared ?
You are right, this would not work in case of shared IRQs. Hovewer this driver is for an embedded arch and the line is not shared.
> > > > > This is different from disabling interrupts on CPU. > > > > mm, Why disabling interrupts in general. Doesn't IRQ hanlers of the same kind got > executed in a serialized fashion even on SMPs ?. If so, why not just wakeup our > custom-thread or use workqueues and let them do their business ?
Because you don't want CPU to be continually interrupted while untill right thread gets scheduled. I think using work[queue] is the best solution for this driver, but you still want to mask that particular IRQ off until you do the read.
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