Linux interrupt managing on 8xx

Linux interrupt managing on 8xx

[DI BACCO ANTONIO - technolabs]

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I have a component named pca9555 (on the i2c bus) that is an I/O expander. It can generate an interrupt to the MPC8xx processor (SIU_IRQ1 pin). This pin will be active till I read registers of pca9555. Because I cannot access the i2c bus in the interrupt handler I queue a work on a work queue. Just at the end of the interrupt handler  should I disable the interrupt on the mpc8xx? I think that otherwise the interrupt will pop up again till I execute the work in the work queue finally reading the pca9555 and shutting off the source of the interrupt.

Bye,
Antonio.

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Re: Linux interrupt managing on 8xx

[Ricardo Scop]

On Monday 04 June 2007 17:37, DI BACCO ANTONIO - technolabs wrote:
> I have a component named pca9555 (on the i2c bus) that is an I/O expander.
> It can generate an interrupt to the MPC8xx processor (SIU_IRQ1 pin). This
> pin will be active till I read registers of pca9555. Because I cannot
> access the i2c bus in the interrupt handler I queue a work on a work queue.
> Just at the end of the interrupt handler  should I disable the interrupt on
> the mpc8xx? I think that otherwise the interrupt will pop up again till I
> execute the work in the work queue finally reading the pca9555 and shutting
> off the source of the interrupt.

Well, why don't you simply program the interrupt to be edge-triggered in the 
SIEL register? This way it will only occur again after the pin level is 
cleared.

HTH,

Ricardo.