Re: [PATCH net-next 10/12] net: hns3: Add handling of MAC tunnel interruption

[tanhuazhong]

On 2019/4/19 19:29, Neil Horman wrote:
> On Fri, Apr 19, 2019 at 11:05:45AM +0800, Huazhong Tan wrote:
> > From: Weihang Li <liweihang@xxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxxxx>
> > Signed-off-by: Peng Li <lipeng321@xxxxxxxxxx>
> > ---
> > <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

This function is not running in interrupt context. When the driver 
recieve the msix interrupt, the irq_handler will schedule a task to call 
this function for querying more information about the msix interrupt.

Best Regards, Huazhong

> .