tree 8816b081041daa9b5f8332b0c803678cbbd04e1f
parent 7807fafa52b990abb321f1212416c71e64523ecb
author David Brownell <dbrownell@users.sourceforge.net> 1228170697 -0800
committer Ingo Molnar <mingo@elte.hu> 1228213529 +0100

genirq: warn when IRQF_DISABLED may be ignored

Impact: emit new warning

We periodically waste time tracking down problems from the genirq
framework not respecting IRQF_DISABLED for some shared IRQ cases.  Linus
views this as "will not fix", but we're still left with the bugs caused by
this misbehavior.

This patch adds a nag message in request_irq(), so that drivers can fix
their IRQ handlers to avoid this problem.

Note that developers will never see the relevant bugs when they run with
LOCKDEP, so it's no wonder these bugs are hard to find.  (That also means
LOCKDEP is overlooking some IRQ-related bugs involving IRQ handlers that
don't set IRQF_DISABLED...)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>