Re: [dpdk-dev] [PATCH V2 2/5] Add Intel FPGA BUS Probe Code

["Gaëtan Rivet" <gaetan.rivet@6wind.com>]

On Wed, Mar 21, 2018 at 03:51:31PM +0800, Rosen Xu wrote:
> Signed-off-by: Rosen Xu <rosen.xu@intel.com>
> ---
>  lib/librte_eal/common/eal_common_bus.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
> index 3e022d5..e3bcebe 100644
> --- a/lib/librte_eal/common/eal_common_bus.c
> +++ b/lib/librte_eal/common/eal_common_bus.c
> @@ -87,7 +87,7 @@ struct rte_bus_list rte_bus_list =
>  rte_bus_probe(void)
>  {
>  	int ret;
> -	struct rte_bus *bus, *vbus = NULL;
> +	struct rte_bus *bus, *vbus = NULL, *ifpga_bus = NULL;
>  
>  	TAILQ_FOREACH(bus, &rte_bus_list, next) {
>  		if (!strcmp(bus->name, "vdev")) {
> @@ -95,6 +95,11 @@ struct rte_bus_list rte_bus_list =
>  			continue;
>  		}
>  
> +		if (!strcmp(bus->name, "ifpga")) {
> +			ifpga_bus = bus;
> +			continue;
> +		}
> +
>  		ret = bus->probe();
>  		if (ret)
>  			RTE_LOG(ERR, EAL, "Bus (%s) probe failed.\n",
> @@ -108,6 +113,13 @@ struct rte_bus_list rte_bus_list =
>  				vbus->name);
>  	}
>  
> +	if (ifpga_bus) {
> +		ret = ifpga_bus->probe();
> +		if (ret)
> +			RTE_LOG(ERR, EAL, "Scan for (%s) bus failed.\n",
> +				ifpga_bus->name);
> +	}
> +

I do not think this solution is generic and scalable anough to get into
common EAL code.

However, I do not think we need to come up with a dependency scheme
(callback registration to check whether proper conditions are met to
proceed with probing).

I think you have a hard-dependency on the PCI bus because you are simply
probing a PCI device. You do not need an additional bus for this.

-- 
Gaëtan Rivet
6WIND