Commit efc36d3c authored Dec 10, 2020 by Loic Poulain Committed by Jakub Kicinski Dec 14, 2020

net: mhi: Fix unexpected queue wake



This patch checks that MHI queue is not full before waking up the net
queue. This fix sporadic MHI queueing issues in xmit. Indeed xmit and
its symmetric complete callback (ul_callback) can run concurently, it
is then not safe to unconditionnaly waking the queue in the callback
without checking queue fullness.

Fixes: 3ffec6a1 ("net: Add mhi-net driver")
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1607599507-5879-1-git-send-email-loic.poulain@linaro.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 49506a9b

drivers/net/mhi_net.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -173,6 +173,7 @@ static void mhi_net_ul_callback(struct mhi_device *mhi_dev,
		{
		struct mhi_net_dev *mhi_netdev = dev_get_drvdata(&mhi_dev->dev);
		struct net_device *ndev = mhi_netdev->ndev;
		struct mhi_device *mdev = mhi_netdev->mdev;
		struct sk_buff *skb = mhi_res->buf_addr;

		/* Hardware has consumed the buffer, so free the skb (which is not
		@@ -196,7 +197,7 @@ static void mhi_net_ul_callback(struct mhi_device *mhi_dev,
		}
		u64_stats_update_end(&mhi_netdev->stats.tx_syncp);

		if (netif_queue_stopped(ndev))
		if (netif_queue_stopped(ndev) && !mhi_queue_is_full(mdev, DMA_TO_DEVICE))
		netif_wake_queue(ndev);
		}

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