Re: [RESEND net-next 1/2] net: hns3: add support for PTP

[huangguangbin (A)]

On 2021/6/3 21:14, Richard Cochran wrote:
> On Wed, Jun 02, 2021 at 10:57:43AM +0800, Guangbin Huang wrote:
>
> > @@ -4342,12 +4352,34 @@ static void hclge_periodic_service_task(struct hclge_dev *hdev)
> >   	hclge_task_schedule(hdev, delta);
> >   }
> >   
> > +static void hclge_ptp_service_task(struct hclge_dev *hdev)
> > +{
> > +	if (!test_bit(HCLGE_STATE_PTP_EN, &hdev->state) ||
> > +	    !test_bit(HCLGE_STATE_PTP_TX_HANDLING, &hdev->state) ||
> > +	    !time_is_before_jiffies(hdev->ptp->tx_start + HZ))
> > +		return;
> > +
> > +	/* to prevent concurrence with the irq handler, disable vector0
> > +	 * before handling ptp service task.
> > +	 */
> > +	disable_irq(hdev->misc_vector.vector_irq);
>
> This won't work.  After all, the ISR thread might already be running.
> Use a proper spinlock instead.
Thanks for review. Using spinlock in irq_handler looks heavy, what about
adding a new flag HCLGE_STATE_PTP_CLEANING_TX_HWTS for hclge_ptp_clean_tx_hwts()?
Function hclge_ptp_clean_tx_hwts() test and set this flag at the beginning
and clean it in the end. Do you think it is Ok?

Thanks,
Guangbin
.

> > +	/* check HCLGE_STATE_PTP_TX_HANDLING here again, since the irq
> > +	 * handler may handle it just before disable_irq().
> > +	 */
> > +	if (test_bit(HCLGE_STATE_PTP_TX_HANDLING, &hdev->state))
> > +		hclge_ptp_clean_tx_hwts(hdev);
> > +
> > +	enable_irq(hdev->misc_vector.vector_irq);
> > +}
>
> Thanks,
> Richard
> .