From 4a9949d7ac9e2bc51939f27b184be6e1bd99004e Mon Sep 17 00:00:00 2001
From: Andy Wingo <wingo@pobox.com>
Date: Wed, 19 Oct 2005 21:23:46 -0700
Subject: [PATCH] [PATCH] raw1394: fix locking in the presence of SMP and
 interrupts

Changes all spinlocks that can be held during an irq handler to disable
interrupts while the lock is held.  Changes spin_[un]lock_irq to use the
irqsave/irqrestore variants for robustness and readability.

In raw1394.c:handle_iso_listen(), don't grab host_info_lock at all -- we're
not accessing host_info_list or host_count, and holding this lock while
trying to tasklet_kill the iso tasklet this can cause an ABBA deadlock if
ohci:dma_rcv_tasklet is running and tries to grab host_info_lock in
raw1394.c:receive_iso.  Test program attached reliably deadlocks all SMP
machines I have been able to test without this patch.

Signed-off-by: Andy Wingo <wingo@pobox.com>
Acked-by: Ben Collins <bcollins@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
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