[dpdk-users] Detect LSC capability of dpdk ports

[John Sucaet]

Thanks, Stephen.

This function rte_eth_has_link_state was exactly what I was looking for. 
As it seems interesting to more people, could it be resubmitted outside 
the patch serie for Hyper-V?

Regards

John

On 27-06-16 18:23, Stephen Hemminger wrote:
> On Mon, 27 Jun 2016 11:55:46 +0200
> John Sucaet <john.sucaet at oneaccess-net.com> wrote:
>
>> Hi,
>>
>> How can a dpdk application determine if a port has support for lsc,
>> before trying to configure it?
>>
>> Thanks
>>
>> John
> We ended up adding this patch, which never seemed to be accepted upstream.
> >From 79060ea428f070f309f577006af43eb4ab74586d Mon Sep 17 00:00:00 2001
> From: Stephen Hemminger <shemming at brocade.com>
> Date: Tue, 3 Feb 2015 17:14:32 -0800
> Subject: [PATCH 1/7] ether: add function to query for link state interrupt
>
> Allow application to query whether link state will work.
> This is also part of abstracting dependency on PCI.
>
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> ---
>   lib/librte_ether/rte_ethdev.c          |   14 ++++++++++++++
>   lib/librte_ether/rte_ethdev.h          |   12 ++++++++++++
>   lib/librte_ether/rte_ether_version.map |    1 +
>   3 files changed, 27 insertions(+)
>
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -1091,6 +1091,23 @@ rte_eth_dev_start(uint8_t port_id)
>   	return 0;
>   }
>   
> +int
> +rte_eth_has_link_state(uint8_t port_id)
> +{
> +	struct rte_eth_dev *dev;
> +
> +	if (!rte_eth_dev_is_valid_port(port_id)) {
> +		RTE_PMD_DEBUG_TRACE("Invalid port_id=%d\n", port_id);
> +		return 0;
> +	}
> +	dev = &rte_eth_devices[port_id];
> +
> +	if (!dev->driver || !dev->pci_dev)
> +		return 0;
> +
> +	return (dev->pci_dev->driver->drv_flags & RTE_PCI_DRV_INTR_LSC) != 0;
> +}
> +
>   void
>   rte_eth_dev_stop(uint8_t port_id)
>   {
> --- a/lib/librte_ether/rte_ethdev.h
> +++ b/lib/librte_ether/rte_ethdev.h
> @@ -2149,6 +2149,18 @@ extern void rte_eth_link_get_nowait(uint
>   				struct rte_eth_link *link);
>   
>   /**
> + * Test whether device supports link state interrupt mode.
> + *
> + * @param port_id
> + *   The port identifier of the Ethernet device.
> + * @return
> + *   - (1) if link state interrupt is supported
> + *   - (0) if link state interrupt is not supported
> + */
> +extern int
> +rte_eth_has_link_state(uint8_t port_id);
> +
> +/**
>    * Retrieve the general I/O statistics of an Ethernet device.
>    *
>    * @param port_id
> --- a/lib/librte_ether/rte_ether_version.map
> +++ b/lib/librte_ether/rte_ether_version.map
> @@ -83,6 +83,7 @@ DPDK_2.2 {
>   	rte_eth_dev_wd_timeout_store;
>   	rte_eth_dma_zone_reserve;
>   	rte_eth_driver_register;
> +	rte_eth_has_link_state;
>   	rte_eth_led_off;
>   	rte_eth_led_on;
>   	rte_eth_link;
>