webrtc-audio-processing: fix build on ARM Cortex-M

The webrtc-audio-processing configure script assumes that if the
host_cpu part of the tuple is "arm", then ARM instructions are
available. This is obviously incorrect for ARM Cortex-M platforms, which
only support the Thumb-2 instruction set.

In order to address this, we add a patch,
0001-configure.ac-fix-architecture-detection.patch, which changes how
webrtc-audio-processing detects the architecture: instead of relying on
the host_cpu part of the tuple, it relies on the built-in definitions of
the compiler.

Not only it fixes the Cortex-M detection, but it also enables ARMv7
optimizations on ARMv7-A: until now they were only enabled when the
host_cpu part of the tuple was armv7, which is never the case in
Buildroot.

However, once this issue is fixed for Cortex-M, the build nonetheless
fails later due to the usage of NPTL-only functions. So we change the
thread dependency to a NPTL dependency.

Fixes:

  http://autobuild.buildroot.net/results/4933082cd7cc5781404c77ccef5c2b9333c5f714/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/package/webrtc-audio-processing/webrtc-audio-processing.mk b/package/webrtc-audio-processing/webrtc-audio-processing.mk
index 587f1aa899..5a5d1ce29b 100644
--- a/package/webrtc-audio-processing/webrtc-audio-processing.mk
+++ b/package/webrtc-audio-processing/webrtc-audio-processing.mk
@@ -10,6 +10,8 @@ WEBRTC_AUDIO_PROCESSING_SITE = http://freedesktop.org/software/pulseaudio/webrtc
 WEBRTC_AUDIO_PROCESSING_INSTALL_STAGING = YES
 WEBRTC_AUDIO_PROCESSING_LICENSE = BSD-3c
 WEBRTC_AUDIO_PROCESSING_LICENSE_FILES = COPYING
+# 0001-configure.ac-fix-architecture-detection.patch
+WEBRTC_AUDIO_PROCESSING_AUTORECONF = YES
 
 ifeq ($(BR2_SOFT_FLOAT),y)
 WEBRTC_AUDIO_PROCESSING_CONF_OPTS += --with-ns-mode=fixed