Re: [dpdk-dev] [PACTH v2 2/2] mlx4: fix shared library dependency

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2015-07-30 16:48, Nelio Laranjeiro:
> librte_pmd_mlx4.so needs to be linked with libiverbs otherwise, the PMD is not
> able to open Mellanox devices and the following message is printed by testpmd
> at startup "librte_pmd_mlx4: cannot access device, is mlx4_ib loaded?".
> 
> Applications dependency on libverbs are moved to be only valid in static mode,
> in shared mode, applications do not depend on it anymore,
> librte_pmd_mlx4.so keeps this dependency and thus is linked with libverbs.
> 
> Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
> Acked-by: Olivier Matz <olivier.matz@6wind.com>
> ---
> Changelog: don't compiled MLX4 PMD when the DPDK is build in combined shared
> library.

MLX4 cannot be supported in combined shared library because there is no clean
way of adding -libverbs to the combined library.
(This comment should be in the commit message)

> --- a/drivers/net/Makefile
> +++ b/drivers/net/Makefile
> @@ -40,7 +40,6 @@ DIRS-$(CONFIG_RTE_LIBRTE_ENIC_PMD) += enic
>  DIRS-$(CONFIG_RTE_LIBRTE_FM10K_PMD) += fm10k
>  DIRS-$(CONFIG_RTE_LIBRTE_I40E_PMD) += i40e
>  DIRS-$(CONFIG_RTE_LIBRTE_IXGBE_PMD) += ixgbe
> -DIRS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4
>  DIRS-$(CONFIG_RTE_LIBRTE_MPIPE_PMD) += mpipe
>  DIRS-$(CONFIG_RTE_LIBRTE_PMD_NULL) += null
>  DIRS-$(CONFIG_RTE_LIBRTE_PMD_PCAP) += pcap
> @@ -49,5 +48,10 @@ DIRS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio
>  DIRS-$(CONFIG_RTE_LIBRTE_VMXNET3_PMD) += vmxnet3
>  DIRS-$(CONFIG_RTE_LIBRTE_PMD_XENVIRT) += xenvirt
>  
> +# Drivers not support in combined mode

This comment is useless.

> +ifeq ($(CONFIG_RTE_BUILD_COMBINE_LIBS),n)

It can be enabled if building a static combined library.

> +DIRS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4

There is no good reason to move this line.