kernel disables interrupts

kernel disables interrupts

[Jim Deas]

I am trouble shooting a new driver and have found a new
kernel item that makes trouble shooting a bit harder.
When I unload my test driver and before I can reload it
(reseting the interrut controls)the Kernerl disables
the chattering interrupt.
Once the kernel has disable a spurious interrupt is there
a way to get it back?

JD

Re: kernel disables interrupts

[Ben Collins]

On Thu, Feb 26, 2004 at 10:25:02AM -0800, Jim Deas wrote:
> I am trouble shooting a new driver and have found a new
> kernel item that makes trouble shooting a bit harder.
> When I unload my test driver and before I can reload it
> (reseting the interrut controls)the Kernerl disables
> the chattering interrupt.
> Once the kernel has disable a spurious interrupt is there
> a way to get it back?

Shouldn't your driver just disable the interrupt before unloading?

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Re: kernel disables interrupts

[Richard B. Johnson]

On Thu, 26 Feb 2004, Jim Deas wrote:

> I am trouble shooting a new driver and have found a new
> kernel item that makes trouble shooting a bit harder.
> When I unload my test driver and before I can reload it
> (reseting the interrut controls)the Kernerl disables
> the chattering interrupt.
> Once the kernel has disable a spurious interrupt is there
> a way to get it back?
>
> JD

Linux version 2.4.24 doesn't "disable" a spurious interrupt!
When you unload the driver, you deallocate the interrupt you
are using (I sure hope so). When you load the driver again,
you reallocate the interrupt. If you FAILED to release the
IRQ when you unloaded the module, guess what? It's still
allocated and you can't have it anymore. That's probably
what's happening.

Cheers,
Dick Johnson
Penguin : Linux version 2.4.24 on an i686 machine (797.90 BogoMips).
            Note 96.31% of all statistics are fiction.

Re: kernel disables interrupts

[Zwane Mwaikambo]

On Thu, 26 Feb 2004, Jim Deas wrote:

> I am trouble shooting a new driver and have found a new
> kernel item that makes trouble shooting a bit harder.
> When I unload my test driver and before I can reload it
> (reseting the interrut controls)the Kernerl disables
> the chattering interrupt.
> Once the kernel has disable a spurious interrupt is there
> a way to get it back?

I take it you're referring to 2.6? Before you disable this feature (doable
via kernel parameter noirqdebug) be sure that you're disabling your device
before exiting the driver.