[dpdk-dev] [PATCH 2/7] net/mlx4: fix Rx interrupts with multiple ports

[Ferruh Yigit]

On 6/14/2017 12:49 PM, Adrien Mazarguil wrote:
> Several Ethernet device structures are allocated on top of a common PCI
> device for mlx4 adapters with multiple ports. These inherit a common
> interrupt handle from their parent PCI device, which prevents Rx interrupts
> from working properly on all ports as their configuration is overwritten.
> 
> Use a local interrupt handle to address this issue.

Hi Adrien,

I am not clear why local copy required, and main concern from my point
of view is if this is a common problem for all PMDs and should be
addressed in higher level?

The variable is already per eth_dev, but this patch moves it the private
data. What overwrites it within eth_dev?

Thanks,
ferruh

> 
> Fixes: 9f05a4b81809 ("net/mlx4: support user space Rx interrupt event")
> 
> Signed-off-by: Adrien Mazarguil <adrien.mazarguil at 6wind.com>
> Acked-by: Moti Haimovsky <motih at mellanox.com>
> ---
>  drivers/net/mlx4/mlx4.c | 9 +++++++++
>  drivers/net/mlx4/mlx4.h | 1 +
>  2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
> index 178562e..2b4722f 100644
> --- a/drivers/net/mlx4/mlx4.c
> +++ b/drivers/net/mlx4/mlx4.c
> @@ -6207,6 +6207,15 @@ mlx4_pci_probe(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
>  
>  		eth_dev->device->driver = &mlx4_driver.driver;
>  
> +		/*
> +		 * Copy and override interrupt handle to prevent it from
> +		 * being shared between all ethdev instances of a given PCI
> +		 * device. This is required to properly handle Rx interrupts
> +		 * on all ports.
> +		 */
> +		priv->intr_handle_dev = *eth_dev->intr_handle;
> +		eth_dev->intr_handle = &priv->intr_handle_dev;
> +
>  		priv->dev = eth_dev;
>  		eth_dev->dev_ops = &mlx4_dev_ops;
>  
> diff --git a/drivers/net/mlx4/mlx4.h b/drivers/net/mlx4/mlx4.h
> index c46fc23..b74fbf8 100644
> --- a/drivers/net/mlx4/mlx4.h
> +++ b/drivers/net/mlx4/mlx4.h
> @@ -345,6 +345,7 @@ struct priv {
>  	unsigned int txqs_n; /* TX queues array size. */
>  	struct rxq *(*rxqs)[]; /* RX queues. */
>  	struct txq *(*txqs)[]; /* TX queues. */
> +	struct rte_intr_handle intr_handle_dev; /* Device interrupt handler. */
>  	struct rte_intr_handle intr_handle; /* Interrupt handler. */
>  	struct rte_flow_drop *flow_drop_queue; /* Flow drop queue. */
>  	LIST_HEAD(mlx4_flows, rte_flow) flows;
>