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Date:   Fri, 19 Apr 2019 07:29:02 -0400
From:   Neil Horman <nhorman@redhat.com>
To:     Huazhong Tan <tanhuazhong@huawei.com>
Cc:     davem@davemloft.net, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, salil.mehta@huawei.com,
        yisen.zhuang@huawei.com, linuxarm@huawei.com,
        Weihang Li <liweihang@hisilicon.com>,
        Peng Li <lipeng321@huawei.com>
Subject: Re: [PATCH net-next 10/12] net: hns3: Add handling of MAC tunnel
 interruption
Message-ID: <20190419112902.GA31368@hmswarspite.think-freely.org>
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 <1555643147-52407-11-git-send-email-tanhuazhong@huawei.com>
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On Fri, Apr 19, 2019 at 11:05:45AM +0800, Huazhong Tan wrote:
> From: Weihang Li <liweihang@hisilicon.com>
> 
> MAC tnl interruptions are different from other type of RAS and MSI-X
> errors, because some bits, such as OVF/LR/RF will occur during link up
> and down.
> 
> The drivers should clear status of all MAC tnl interruption bits but
> shouldn't print any message that would mislead the users.
> 
> In case that link down and re-up in a short time because of some reasons,
> we record when they occurred, and users can query them by debugfs.
> 
> Signed-off-by: Weihang Li <liweihang@hisilicon.com>
> Signed-off-by: Peng Li <lipeng321@huawei.com>
> ---
><snip>>
>  					     bool en)
>  {
> @@ -1611,6 +1636,7 @@ pci_ers_result_t hclge_handle_hw_ras_error(struct hnae3_ae_dev *ae_dev)
>  int hclge_handle_hw_msix_error(struct hclge_dev *hdev,
>  			       unsigned long *reset_requests)
>  {
> +	struct hclge_mac_tnl_stats mac_tnl_stats;
>  	struct device *dev = &hdev->pdev->dev;
>  	u32 mpf_bd_num, pf_bd_num, bd_num;
>  	enum hnae3_reset_type reset_level;
> @@ -1745,6 +1771,31 @@ int hclge_handle_hw_msix_error(struct hclge_dev *hdev,
>  		set_bit(HNAE3_GLOBAL_RESET, reset_requests);
>  	}
>  
> +	/* query and clear mac tnl interruptions */
> +	hclge_cmd_setup_basic_desc(&desc[0], HCLGE_OPC_QUERY_MAC_TNL_INT,
> +				   true);
> +	ret = hclge_cmd_send(&hdev->hw, &desc[0], 1);
Is this running in interrupt context ever?  I don't think it is, but the
function name makes me think otherwise.  If it is, this could be unsafe as you
take a spinlock in hclge_cmd_send, which is protected against bottom halves, but
not interrupts.  That could cause a deadlock if there is a path to get here
directly from an interrupt context.
Neil