Re: [PATCH] 2.6.18-rt7: PowerPC: fix breakage in threaded fasteoitype IRQ handlers

From: Sergei Shtylyov
Date: Mon Nov 20 2006 - 12:02:25 EST


Hello.

Ingo Molnar wrote:

on PPC64, 'get the vector' initiates an ACK as well - is that done before handle_irq() is done?

Exactly. How else do_IRQ() would know the vector?

the reason i'm asking is that in this case masking is a bit late at this point and there's a chance for a repeat interrupt.

How's that? Acknowledge != EOI on OpenPIC (as well as 8259).
Acknoledging sets the bit in the in-service register preventing all the interrupts with same or lower prioriry from being accepted.

Ingo

WBR, Sergei
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