From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivan Khoronzhuk Subject: [PATCH v4 2/5] net: ethernet: ti: davinci_cpdma: fix locking while ctrl_stop Date: Mon, 22 Aug 2016 21:18:25 +0300 Message-ID: <1471889908-29983-3-git-send-email-ivan.khoronzhuk@linaro.org> References: <1471889908-29983-1-git-send-email-ivan.khoronzhuk@linaro.org> Cc: linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, nsekhar@ti.com, dlide@ti.com, Ivan Khoronzhuk To: davem@davemloft.net, netdev@vger.kernel.org, mugunthanvnm@ti.com, grygorii.strashko@ti.com Return-path: Received: from mail-lf0-f43.google.com ([209.85.215.43]:32866 "EHLO mail-lf0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754126AbcHVSSj (ORCPT ); Mon, 22 Aug 2016 14:18:39 -0400 Received: by mail-lf0-f43.google.com with SMTP id b199so84151571lfe.0 for ; Mon, 22 Aug 2016 11:18:38 -0700 (PDT) In-Reply-To: <1471889908-29983-1-git-send-email-ivan.khoronzhuk@linaro.org> Sender: netdev-owner@vger.kernel.org List-ID: 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 Signed-off-by: Ivan Khoronzhuk --- drivers/net/ethernet/ti/davinci_cpdma.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c index 167fd65..ffb32af 100644 --- a/drivers/net/ethernet/ti/davinci_cpdma.c +++ b/drivers/net/ethernet/ti/davinci_cpdma.c @@ -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); -- 1.9.1