Messages in this thread | | | Subject | Re: [PATCH 2.6.16] Shared interrupts sometimes lost | From | Lee Revell <> | Date | Sat, 08 Apr 2006 12:31:36 -0400 |
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On Sat, 2006-04-08 at 14:10 +1000, Neil Brown wrote: > > To explain what I think is happening, let me start with a very simple > case. A number of PCI devices (this one included) have a number of > events which can trigger an interrupt. The events which are current > are presented as bits in a register, and are ORed together (and > possibly masked by another register) to make the IRQ line. > When 1's are written to any bits in this register, it acknowledges > the event and clears the bit. > A typical code fragment is > events = read_register(INTERRUPTS); > write_register(INTERRUPTS, events); > ... handle each 1 bits in events .... >
Isn't a more typical IRQ handler:
while (events = read_register(INTERRUPTS) != 0) { ...handle each bit in events and ACK it... }
Lee
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