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Date: Tue, 27 Sep 2011 16:59:28 +0300
From: Felix Radensky <felix@embedded-sol.com>
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To: "linuxppc-dev@ozlabs.org" <linuxppc-dev@ozlabs.org>,
	"jacmet@sunsite.dk" <jacmet@sunsite.dk>, grant.likely@secretlab.ca
Subject: Handling multiple GPIO controllers in 8xxx GPIO driver
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Hi,

Looks like  8xxx GPIO driver cannot properly handle interrupts
when multiple GPIO controllers exist in the system.

On Freescale P1022 there are 3 GPIO controllers. All 3 use
the same interrupt line, internal interrupt 31. If all controllers
are defined in device tree set_irq_chained_handler() is invoked
3 times with same  hardware irq number. The result is interrupt
storm,  mpc8xxx_gpio_irq_cascade() is invoked indefinitely.

What would be the best way to fix the problem ?

Thanks.

Felix Radensky.