[dpdk-stable] [PATCH] pci: fix missing pci bus with shared library build

[Stephen Hemminger]

On Mon, 15 Jul 2019 16:41:36 -0700
Stephen Hemminger <stephen at networkplumber.org> wrote:

> If DPDK is built as a shared library, then any application linked
> with rte.app.mk will not find any PCI devices. When the application
> is started no ethernet devices are found.
> 
> This is because the link order of libraries on the command line matters.
> And PCI is before EAL. That causes there to be no dependency on PCI
> so linker ignores linking the library. 
> Swapping the order fixes this.
> 
> Fixes: c752998b5e2e ("pci: introduce library and driver")
> Cc: stable at dpdk.org
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> ---
>  mk/rte.app.mk | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mk/rte.app.mk b/mk/rte.app.mk
> index a277c808ed8e..470b92e4d73e 100644
> --- a/mk/rte.app.mk
> +++ b/mk/rte.app.mk
> @@ -90,8 +90,8 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_STACK)          += -lrte_stack
>  _LDLIBS-$(CONFIG_RTE_DRIVER_MEMPOOL_RING)   += -lrte_mempool_ring
>  _LDLIBS-$(CONFIG_RTE_LIBRTE_OCTEONTX2_MEMPOOL) += -lrte_mempool_octeontx2
>  _LDLIBS-$(CONFIG_RTE_LIBRTE_RING)           += -lrte_ring
> -_LDLIBS-$(CONFIG_RTE_LIBRTE_PCI)            += -lrte_pci
>  _LDLIBS-$(CONFIG_RTE_LIBRTE_EAL)            += -lrte_eal
> +_LDLIBS-$(CONFIG_RTE_LIBRTE_PCI)            += -lrte_pci
>  _LDLIBS-$(CONFIG_RTE_LIBRTE_CMDLINE)        += -lrte_cmdline
>  _LDLIBS-$(CONFIG_RTE_LIBRTE_REORDER)        += -lrte_reorder
>  _LDLIBS-$(CONFIG_RTE_LIBRTE_SCHED)          += -lrte_sched

It still happens with 19.08. Testpmd works but only because it is
linked with so many things. But l3fwd fails...

# ./examples/l3fwd/build/l3fwd -n4 -l0-3 -w 02:00.0
EAL: Detected 8 lcore(s)
EAL: Detected 1 NUMA nodes
EAL: failed to parse device "02:00.0"
EAL: Unable to parse device '02:00.0'
EAL: Error - exiting with code: 1
  Cause: Invalid EAL parameters