Messages in this thread | | | Date | Tue, 18 Apr 2017 14:54:32 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 06/38] Annotate hardware config module parameters in drivers/clocksource/ |
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On Tue, 18 Apr 2017, David Howells wrote: > Thomas Gleixner <tglx@linutronix.de> wrote: > > > > > > Btw, is it possible to use IRQ grants to prevent a device that has limited > > > > > IRQ options from being drivable? > > > > > > > > What do you mean with 'IRQ grants' ? > > > > > > request_irq(). > > > > I still can't parse the sentence above. If request_irq() fails the device > > initialization fails. If you request the wrong irq then request_irq() might > > succeed but the device won't work. > > I was talking about having using a driver to make request_irq() grant an irq > to that driver so that another driver can't bind to its device because all its > irq options are taken and the irqs can't be shared.
Yes. That's possible.
init_driver1() request_irq(X, flags,.....);
init_driver2() request_irq(X, flags,.....);
The second driver can fail, when flags are not matching. That might be disagreement about SHARED or the trigger type, i.e. egde vs. level.
Thanks,
tglx
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