Re: [dpdk-stable] [PATCH] net/ixgbe: fix blocked interrupts

[Yuanhan Liu <yuanhan.liu@intel.com>]

On Sun, Feb 19, 2017 at 04:52:50PM -0500, Qi Zhang wrote:
> [ backported from upstream commit 9b667210700e6b52a123cc5b36d0a3b0b3aa7c94 ]

Thanks for the packport, and applied to dpdk-stable/16.11.

	--yliu

> While handling link status change (LSC) interrupt, all interrupts are
> blocked until delayed interrupt handler finishes.
> The wait duration is at least one second and this may cause timeouts in
> VF to PF mailbox.
> Make sure only LSC interrupt is blocked while waiting for delayed
> interrupt handler to finish.
> 
> Fixes: 0a45657a6794 ("pci: rework interrupt handling")
> 
> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
> ---
>  drivers/net/ixgbe/ixgbe_ethdev.c | 18 ++++++++----------
>  drivers/net/ixgbe/ixgbe_ethdev.h |  2 ++
>  2 files changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
> index dbfb0c0..bac36e0 100644
> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> @@ -3474,7 +3474,6 @@ ixgbe_dev_interrupt_action(struct rte_eth_dev *dev)
>  		IXGBE_DEV_PRIVATE_TO_INTR(dev->data->dev_private);
>  	int64_t timeout;
>  	struct rte_eth_link link;
> -	int intr_enable_delay = false;
>  	struct ixgbe_hw *hw =
>  		IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
>  
> @@ -3507,20 +3506,19 @@ ixgbe_dev_interrupt_action(struct rte_eth_dev *dev)
>  			timeout = IXGBE_LINK_DOWN_CHECK_TIMEOUT;
>  
>  		ixgbe_dev_link_status_print(dev);
> -
> -		intr_enable_delay = true;
> -	}
> -
> -	if (intr_enable_delay) {
> +		intr->mask_original = intr->mask;
> +		/* only disable lsc interrupt */
> +		intr->mask &= ~IXGBE_EIMS_LSC;
>  		if (rte_eal_alarm_set(timeout * 1000,
>  				      ixgbe_dev_interrupt_delayed_handler, (void *)dev) < 0)
>  			PMD_DRV_LOG(ERR, "Error setting alarm");
> -	} else {
> -		PMD_DRV_LOG(DEBUG, "enable intr immediately");
> -		ixgbe_enable_intr(dev);
> -		rte_intr_enable(&(dev->pci_dev->intr_handle));
> +		else
> +			intr->mask = intr->mask_original;
>  	}
>  
> +	PMD_DRV_LOG(DEBUG, "enable intr immediately");
> +	ixgbe_enable_intr(dev);
> +	rte_intr_enable(&dev->pci_dev->intr_handle);
>  
>  	return 0;
>  }
> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.h b/drivers/net/ixgbe/ixgbe_ethdev.h
> index 4ff6338..a4e2996 100644
> --- a/drivers/net/ixgbe/ixgbe_ethdev.h
> +++ b/drivers/net/ixgbe/ixgbe_ethdev.h
> @@ -165,6 +165,8 @@ struct ixgbe_hw_fdir_info {
>  struct ixgbe_interrupt {
>  	uint32_t flags;
>  	uint32_t mask;
> +	/*to save original mask during delayed handler */
> +	uint32_t mask_original;
>  };
>  
>  struct ixgbe_stat_mapping_registers {
> -- 
> 2.7.4