diff options
| author | Andy Wingo <wingo@pobox.com> | 2005-10-19 21:23:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-10-19 23:04:30 -0700 |
| commit | 4a9949d7ac9e2bc51939f27b184be6e1bd99004e (patch) | |
| tree | 85f67b527d3ff5a550ada8e08600f1400ddc5960 /drivers/ieee1394/ohci1394.c | |
| parent | c367c21c93ccdaf7e1e124891633d89f9ae77f54 (diff) | |
| download | op-kernel-dev-4a9949d7ac9e2bc51939f27b184be6e1bd99004e.zip op-kernel-dev-4a9949d7ac9e2bc51939f27b184be6e1bd99004e.tar.gz | |
[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>
Diffstat (limited to 'drivers/ieee1394/ohci1394.c')
| -rw-r--r-- | drivers/ieee1394/ohci1394.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/ieee1394/ohci1394.c b/drivers/ieee1394/ohci1394.c index 6a6acbd..4cf9b8f 100644 --- a/drivers/ieee1394/ohci1394.c +++ b/drivers/ieee1394/ohci1394.c @@ -2283,8 +2283,9 @@ static void ohci_schedule_iso_tasklets(struct ti_ohci *ohci, { struct ohci1394_iso_tasklet *t; unsigned long mask; + unsigned long flags; - spin_lock(&ohci->iso_tasklet_list_lock); + spin_lock_irqsave(&ohci->iso_tasklet_list_lock, flags); list_for_each_entry(t, &ohci->iso_tasklet_list, link) { mask = 1 << t->context; @@ -2295,8 +2296,7 @@ static void ohci_schedule_iso_tasklets(struct ti_ohci *ohci, tasklet_schedule(&t->tasklet); } - spin_unlock(&ohci->iso_tasklet_list_lock); - + spin_unlock_irqrestore(&ohci->iso_tasklet_list_lock, flags); } static irqreturn_t ohci_irq_handler(int irq, void *dev_id, |
