Messages in this thread | | | Date | Sat, 29 Apr 2006 14:58:16 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: better leve triggered IRQ management needed |
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On Sat, 29 Apr 2006, Alan Cox wrote: > > Trying to guess the current IRQ level v edge on a PC is very hard. > Trying to set it correctly from the driver is rather easier.
I disagree. It's not any easier at all.
On PC's (x86 and x86-64) we actually already set the ELCR as well as we can (look for "eisa_set_level_irq()"). And a driver _literally_ cannot change it from the system value, because of the polarity confusion.
In the other cases (IO-APIC) we usually have it level, but when we have it marked as an edge, there is almost always a real reason for that too (ie legacy interrupt, it really _is_ edge-high, not level-low).
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