From 2d9f199061fa0629847b63e6b6317a7b12a9d99f Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Mon, 29 May 2017 23:31:51 +0200 Subject: [PATCH] ffmpeg: do not build on m68k coldfire m68k coldfire causes ffmpeg to think atomic intrinsics are available, so ffmpeg doesn't use its fallback on pthreads based atomic operations. However, m68k coldfire doesn't provide properly working sync 4 atomics, causing a build failure. Since fixing ffmpeg on m68k coldfire is not really important (who wants to use ffmpeg on such platform?), we simply disallow the selection of ffmpeg on this platform. Alternate approaches have been proposed in the past: - Bernd Kuhls proposed in http://patchwork.ozlabs.org/patch/766909/ to add a dependency on BR2_TOOLCHAIN_HAS_SYNC_4, but this is wrong because other architectures that lack sync 4 atomics, such as Sparc, can build ffmpeg perfectly fine thanks to the pthreads based fallback code. - Waldemar Brodkorb proposed in https://patchwork.ozlabs.org/patch/756664/ to add an explicit option in ffmpeg configure to force the use of pthreads based atomics. However, we believe that running ffmpeg on m68k coldfire is such an unlikely use case that it isn't worth carrying a patch for this. Fixes: http://autobuild.buildroot.net/results/b3e/b3eaaf6d73cd49f5919143aeaa5cbb4d15a7ccc3/ Signed-off-by: Thomas Petazzoni --- package/ffmpeg/Config.in | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/package/ffmpeg/Config.in b/package/ffmpeg/Config.in index 383374ddbe..279f94f0d1 100644 --- a/package/ffmpeg/Config.in +++ b/package/ffmpeg/Config.in @@ -3,7 +3,13 @@ config BR2_PACKAGE_FFMPEG_ARCH_SUPPORTS # fenv.h lacks FE_INVALID, FE_OVERFLOW & FE_UNDERFLOW on nios2 # No support for ARMv7-M in the ARM assembly logic # Microblaze build affected by gcc PR71124 (infinite loop) - default y if !BR2_nios2 && !BR2_ARM_CPU_ARMV7M && !BR2_microblaze + # m68k coldfire causes a build failure, because the check for + # atomics (atomic_store) succeeds, which causes ffmpeg to + # think atomic intrinsics are available, while they are + # not. See https://patchwork.ozlabs.org/patch/756664/ and + # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68467 for more + # details. + default y if !BR2_nios2 && !BR2_ARM_CPU_ARMV7M && !BR2_microblaze && !BR2_m68k_cf menuconfig BR2_PACKAGE_FFMPEG bool "ffmpeg" -- 2.30.2