Re: [dpdk-dev] [PATCH] net/ixgbe: fix link status inconsistencies

["Zhu, TaoX" <taox.zhu@intel.com>]

+Xiaolong

BR,
Zhu, Tao

> -----Original Message-----
> From: Zhu, TaoX
> Sent: Wednesday, February 26, 2020 8:07 PM
> To: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Lu, Wenzhuo
> <wenzhuo.lu@intel.com>
> Cc: dev@dpdk.org; Zhu, TaoX <taox.zhu@intel.com>; stable@dpdk.org
> Subject: [PATCH] net/ixgbe: fix link status inconsistencies
> 
> From: Zhu Tao <taox.zhu@intel.com>
> 
> Setting LINK UP or LINK DOWN is divided into two parts, with the main task
> done in a separate thread, which can take up to 9 seconds. If cancel the
> thread in execution, may cause state inconsistencies. Therefore, must wait
> for the previous setting to exit normally before setting the new state.
> 
> Note: before using threads, use alarm to handle main tasks.
> When canceling alarm, the execution of alarm will not be interrupted.
> 
> Fixes: 819d0d1d57 ("net/ixgbe: fix blocking system events")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Zhu Tao <taox.zhu@intel.com>
> ---
>  drivers/net/ixgbe/ixgbe_ethdev.c | 24 ++++++++++++++++++++++--
>  1 file changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
> b/drivers/net/ixgbe/ixgbe_ethdev.c
> index 23b3f5b0c..2c5797635 100644
> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> @@ -4143,16 +4143,35 @@ ixgbevf_check_link(struct ixgbe_hw *hw,
> ixgbe_link_speed *speed,
>  	return ret_val;
>  }
> 
> +/* return 1: setup complete, return 0: setup not complete, and wait
> +timeout*/ static int ixgbe_dev_wait_setup_link_complete(struct
> +rte_eth_dev *dev) { #define DELAY_INTERVAL 100 /* 100ms */
> +#define MAX_TIMEOUT    90 /* 9s (90 * 100ms) in total */
> +	struct ixgbe_adapter *ad = dev->data->dev_private;
> +	int timeout = MAX_TIMEOUT;
> +
> +	while (rte_atomic32_read(&ad->link_thread_running) && timeout) {
> +		msec_delay(DELAY_INTERVAL);
> +		timeout--;
> +	}
> +
> +
> +	return !!timeout;
> +}
> +
>  static void
>  ixgbe_dev_cancel_link_thread(struct rte_eth_dev *dev)  {
>  	struct ixgbe_adapter *ad = dev->data->dev_private;
>  	void *retval;
> 
> -	if (rte_atomic32_read(&ad->link_thread_running)) {
> +	if (!ixgbe_dev_wait_setup_link_complete(dev)) {
>  		pthread_cancel(ad->link_thread_tid);
>  		pthread_join(ad->link_thread_tid, &retval);
>  		rte_atomic32_clear(&ad->link_thread_running);
> +		PMD_DRV_LOG(ERR, "Link thread not complete, cancel it!");
>  	}
>  }
> 
> @@ -4263,7 +4282,8 @@ ixgbe_dev_link_update_share(struct rte_eth_dev
> *dev,
>  	if (link_up == 0) {
>  		if (ixgbe_get_media_type(hw) == ixgbe_media_type_fiber)
> {
>  			intr->flags |= IXGBE_FLAG_NEED_LINK_CONFIG;
> -			if (rte_atomic32_test_and_set(&ad-
> >link_thread_running)) {
> +			if (ixgbe_dev_wait_setup_link_complete(dev) &&
> +			    rte_atomic32_test_and_set(&ad-
> >link_thread_running)) {
>  				if (rte_ctrl_thread_create(&ad-
> >link_thread_tid,
>  					"ixgbe-link-handler",
>  					NULL,
> --
> 2.17.1