[lkml]   [2006]   [Apr]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: better leve triggered IRQ management needed

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).

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2009-11-18 23:46    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean