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

[Richard Cochran]

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.

> +	/* 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