[ovs-dev] [PATCH v1] acinclude: Remove default library for DPDK.

[Sunil Pai G]

The default DPDK library used before this patch
in case pkg-config fails to find libdpdk is only
valid for make based DPDK builds. Hence remove them.

As a consequence, now this error message [1] is thrown
when pkg-config cannot find libdpdk instead of proceeding
to check for a faulty pkg-config and reporting
incorrect error message [2].

Also, update the documentation to force the user to export
PKG_CONFIG_PATH since on some systems, the default
install path for DPDK libraries is not present in the default
search path of pkg-config.
Ex: for Fedora 32
default pkg-config search path:
/usr/lib64/pkgconfig:/usr/share/pkgconfig

while by default Meson installs DPDK libraries at:
/usr/local/lib64/pkgconfig

[1] Package libdpdk was not found in the pkg-config search path.
    Perhaps you should add the directory containing `libdpdk.pc'
    to the PKG_CONFIG_PATH environment variable
    Package 'libdpdk', required by 'virtual:world', not found

[2] checking for DPDK... no
    checking for faulty pkg-config version... yes
    configure: error: Please upgrade pkg-config

Fixes: 252e1e576443 ("dpdk: Update to use DPDK v20.11.")
Tested-at: https://github.com/Sunil-Pai-G/ovs/actions/runs/498553105
Signed-off-by: Sunil Pai G <sunil.pai.g at intel.com>
---
 Documentation/intro/install/dpdk.rst | 5 ++---
 acinclude.m4                         | 8 ++------
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/Documentation/intro/install/dpdk.rst b/Documentation/intro/install/dpdk.rst
index a595417ce..37910ba33 100644
--- a/Documentation/intro/install/dpdk.rst
+++ b/Documentation/intro/install/dpdk.rst
@@ -87,6 +87,7 @@ Install DPDK
        $ ninja -C build
        $ sudo ninja -C build install
        $ sudo ldconfig
+       $ export PKG_CONFIG_PATH=/path/to/installed/".pc" file/for/DPDK
 
    Detailed information can be found at `DPDK documentation`_.
 
@@ -97,11 +98,9 @@ Install DPDK
 
    Exporting the path to library is not necessary if the DPDK libraries are
    system installed. For libraries installed using a prefix, export the path
-   to this library and also update the $PKG_CONFIG_PATH for use
-   before building OVS::
+   to this library::
 
       $ export LD_LIBRARY_PATH=/path/to/installed/DPDK/libraries
-      $ export PKG_CONFIG_PATH=/path/to/installed/".pc" file/for/DPDK
 
    .. note::
 
diff --git a/acinclude.m4 b/acinclude.m4
index a67e397b6..435685c93 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -350,16 +350,12 @@ AC_DEFUN([OVS_CHECK_DPDK], [
       "shared")
           PKG_CHECK_MODULES([DPDK], [libdpdk], [
               DPDK_INCLUDE="$DPDK_CFLAGS"
-              DPDK_LIB="$DPDK_LIBS"], [
-              DPDK_INCLUDE="-I/usr/local/include/dpdk -I/usr/include/dpdk"
-              DPDK_LIB="-ldpdk"])
+              DPDK_LIB="$DPDK_LIBS"])
               ;;
       "static" | "yes")
           PKG_CHECK_MODULES_STATIC([DPDK], [libdpdk], [
               DPDK_INCLUDE="$DPDK_CFLAGS"
-              DPDK_LIB="$DPDK_LIBS"], [
-              DPDK_INCLUDE="-I/usr/local/include/dpdk -I/usr/include/dpdk"
-              DPDK_LIB="-ldpdk"])
+              DPDK_LIB="$DPDK_LIBS"])
 
           dnl Statically linked private DPDK objects of form
           dnl -l:file.a must be positioned between
-- 
2.25.1