Messages in this thread Patch in this message | | | Subject | [PATCH 4/6] UML - Lock the irqs_to_free list | Date | Fri, 29 Dec 2006 18:41:30 -0500 | From | Jeff Dike <> |
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Fix (i.e. add some) the locking around the irqs_to_free list.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
-- arch/um/drivers/chan_kern.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-)
Index: linux-2.6.18-mm/arch/um/drivers/chan_kern.c =================================================================== --- linux-2.6.18-mm.orig/arch/um/drivers/chan_kern.c 2006-12-29 15:27:16.000000000 -0500 +++ linux-2.6.18-mm/arch/um/drivers/chan_kern.c 2006-12-29 16:38:43.000000000 -0500 @@ -222,15 +222,28 @@ void enable_chan(struct line *line) } } +/* Items are added in IRQ context, when free_irq can't be called, and + * removed in process context, when it can. + * This handles interrupt sources which disappear, and which need to + * be permanently disabled. This is discovered in IRQ context, but + * the freeing of the IRQ must be done later. + */ +static DEFINE_SPINLOCK(irqs_to_free_lock); static LIST_HEAD(irqs_to_free); void free_irqs(void) { struct chan *chan; + LIST_HEAD(list); + struct list_head *ele; + + spin_lock_irq(&irqs_to_free_lock); + list_splice_init(&irqs_to_free, &list); + INIT_LIST_HEAD(&irqs_to_free); + spin_unlock_irq(&irqs_to_free_lock); - while(!list_empty(&irqs_to_free)){ - chan = list_entry(irqs_to_free.next, struct chan, free_list); - list_del(&chan->free_list); + list_for_each(ele, &list){ + chan = list_entry(ele, struct chan, free_list); if(chan->input) free_irq(chan->line->driver->read_irq, chan); @@ -246,7 +259,9 @@ static void close_one_chan(struct chan * return; if(delay_free_irq){ + spin_lock_irq(&irqs_to_free_lock); list_add(&chan->free_list, &irqs_to_free); + spin_unlock_irq(&irqs_to_free_lock); } else { if(chan->input) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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