Commit fccd5bad authored Jul 28, 2016 by Grygorii Strashko Committed by David S. Miller Jul 30, 2016

net: ethernet: ti: cpdma: fix lockup in cpdma_ctlr_destroy()



Fix deadlock in cpdma_ctlr_destroy() which is triggered now on
cpsw module removal:
 cpsw_remove()
 - cpdma_ctlr_destroy()
   - spin_lock_irqsave(&ctlr->lock, flags)
   - cpdma_ctlr_stop()
     - spin_lock_irqsave(&ctlr->lock, flags);
   - cpdma_chan_destroy()
     - spin_lock_irqsave(&ctlr->lock, flags);

The issue has not been observed before because CPDMA channels have
been destroyed manually by CPSW until commit d941ebe8 ("net:
ethernet: ti: cpsw: use destroy ctlr to destroy channels") was merged.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent c882219a

drivers/net/ethernet/ti/davinci_cpdma.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -357,13 +357,11 @@ EXPORT_SYMBOL_GPL(cpdma_ctlr_stop);

		int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
		{
		unsigned long flags;
		int ret = 0, i;

		if (!ctlr)
		return -EINVAL;

		spin_lock_irqsave(&ctlr->lock, flags);
		if (ctlr->state != CPDMA_STATE_IDLE)
		cpdma_ctlr_stop(ctlr);

		@@ -371,7 +369,6 @@ int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
		cpdma_chan_destroy(ctlr->channels[i]);

		cpdma_desc_pool_destroy(ctlr->pool);
		spin_unlock_irqrestore(&ctlr->lock, flags);
		return ret;
		}
		EXPORT_SYMBOL_GPL(cpdma_ctlr_destroy);