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net: ethernet: ti: davinci_cpdma: fix locking while ctrl_stop

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The interrupts shouldn't be disabled while receiving skb, but while
ctrl_stop, the channels are stopped and all remaining packets are
handled with netif_receive_skb(), it can cause WARN_ONCE when ctrl
is stopping while not all packets were handled with NAPIs:

lock_irq_save
    cpdma_ctlr_stop
       cpdma_chan_top
           __cpdma_chan_free
               cpsw_rx_handler
                   netif_receive_skb

So, split locking while ctrl stop thus interrupts are still
enabled while skbs handling. It can cause WARN_ONCE in rare
cases when ctrl is stopping while not all packets were handled
with NAPIs.

Reviewed-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ivan Khoronzhuk 2016-08-22 21:18:25 +03:00 committed by David S. Miller
parent 3802dce178
commit 080d5c5ac8
1 changed files with 2 additions and 0 deletions
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2
drivers/net/ethernet/ti/davinci_cpdma.c
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@ -334,12 +334,14 @@ int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
}
ctlr->state = CPDMA_STATE_TEARDOWN;
spin_unlock_irqrestore(&ctlr->lock, flags);
for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
if (ctlr->channels[i])
cpdma_chan_stop(ctlr->channels[i]);
}
spin_lock_irqsave(&ctlr->lock, flags);
dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);