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Commit 72be12f0 authored by Dan Williams's avatar Dan Williams
Browse files

iop-adma: fix lockdep false positive 



lockdep correctly identifies a potential recursive locking case for
iop_chan->lock, but in the dependency submission case we expect that the same
class will be acquired for both the parent dependency and the child channel.

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 507fbec4

drivers/dma/iop-adma.c

+6 −1
Original line number Diff line number Diff line
@@ -288,7 +288,12 @@ static void iop_adma_tasklet(unsigned long data) 
{

	struct iop_adma_chan *iop_chan = (struct iop_adma_chan *) data;



	spin_lock(&iop_chan->lock);

	/* lockdep will flag depedency submissions as potentially

	 * recursive locking, this is not the case as a dependency

	 * submission will never recurse a channels submit routine.

	 * There are checks in async_tx.c to prevent this.

	 */

	spin_lock_nested(&iop_chan->lock, SINGLE_DEPTH_NESTING);

	__iop_adma_slot_cleanup(iop_chan);

	spin_unlock(&iop_chan->lock);

}