[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>
Showing
Please register or sign in to comment