Re: [PATCH 2.6.16] Shared interrupts sometimes lost
- From: Lee Revell <rlrevell@xxxxxxxxxxx>
- Date: Sat, 08 Apr 2006 12:31:36 -0400
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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
- Follow-Ups:
- Re: [PATCH 2.6.16] Shared interrupts sometimes lost
- From: Neil Brown
- Re: [PATCH 2.6.16] Shared interrupts sometimes lost
- References:
- [PATCH 2.6.16] Shared interrupts sometimes lost
- From: Neil Brown
- [PATCH 2.6.16] Shared interrupts sometimes lost
- Prev by Date: Re: Black box flight recorder for Linux
- Next by Date: Re: 40% IDE performance regression going from FC3 to FC5 with same kernel
- Previous by thread: [PATCH 2.6.16] Shared interrupts sometimes lost
- Next by thread: Re: [PATCH 2.6.16] Shared interrupts sometimes lost
- Index(es):
Relevant Pages
|
