genirq: warn when IRQF_DISABLED may be ignored

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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>

...

This commit is contained in:

David Brownell 2008-12-01 14:31:37 -08:00 • committed by Ingo Molnar

parent 7807fafa52

commit 470c66239e

1 changed files with 12 additions and 0 deletions

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kernel/irq/manage.c

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