sbc: Use extended inline assembly for armv6 primitives

What happened to this[1] patch? Did it fall by the wayside?

I can reproduce the issue this patch addresses. It was also reported here[2] with gdb traces.

I've tested this patch with Alpine Linux on the current edge release. Alpine currently uses sbc 1.4 and gcc 8. Before this patch bluetooth a2dp audio will segmentation fault in sbc_analyze_eight_armv6. After this patch the armv6 assembly code does not crash and a2dp audio streaming works.

PS: I'm not certain how to properly send this as reply to the original patch mail so I've referenced the original this way.

[1] https://marc.info/?l=linux-bluetooth&m=152535913710490
[2] https://bugzilla.redhat.com/show_bug.cgi?format=multiple&id=1350490

Resent due to HTML rejected.

Hi,

I am the original patch author.

I submitted the patch to the mailing list but received no response from a maintainer.

I am using the sbc codec in an embedded project and have to maintain other patches for it anyway, so it was of low priority to get the fix merged for me.

I previously submitted another arm related patch to the sbc library and it was also not merged (although it did get an initial response, just no follow through).

I get the impression the maintainers are simply busy elsewhere - the sbc library code has remain unchanged aside from a single line bugfix since 2014.

I also submitted a bug to gcc, since the issue was clearly a regression in a newer compiler version.

You can find that bug here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85593

There was actually a patch made for the bug recently - so it may soon be resolved in gcc trunk. Although that doesn't do much to fix the issue for anyone using the compiler they have today.

I have not had opportunity to test the patch for gcc to see if it does indeed fix the issue in the sbc code unfortunately.

Cheers,
Austin Morton