Re: [OE-core] RFC: pulseaudio vs. meson vs. neon

["Andrea Adami" <andrea.adami@gmail.com>]

On Mon, Jun 28, 2021 at 7:55 PM Khem Raj <raj.khem@gmail.com> wrote:
>
> Hi Andrea
>
> On 6/28/21 3:01 AM, Andrea Adami wrote:
> > Hello,
> >
> > during a core-image-sato build for armv4 I got one single build
> > failure with pulseaudio.
> >
> > This happens after commit 80bbea0 pulseaudio: switch build system from
> > Autotools to Meson. In the commit text it is evidenced:
> >
> > "
> > With Meson there's no option for disabling Neon optimizations if the
> > compiler supports Neon. If -mfpu is set in CC or CFLAGS, it's ignored,
> > because the build system adds -mfpu=neon at the end of the compiler
> > command line, overriding any earlier -mfpu options. This shouldn't be
> > a problem, because PulseAudio detects at runtime whether the CPU
> > supports Neon instructions.
> > "
> >
> > At the moment to build pulseaudio for armv4/5 I have reverted to using
> > autotools.
> >
> >
> > There was around a patch but has not been merged.
> > https://lists.openembedded.org/g/openembedded-core/message/146375
> >
>
> this patch is not right. It might let us compile but it will still emit
> code that will expect VFP at runtime and hence fail to run.
>
> > Maybe a v2 will be accepted?
>
> right fix would be to add a proper neon support check in pulseaudio
> meson'ary, and if PA has dropped the ball on non VFP ARM then it will be
> hard to convince upstream to accept it but atleast you can try.
>

Thank you for the review.
I knew the patch was not right, I tried other workarounds and I
failed. That's why the RFC was sent.

With my very limited knowledge about the matter it would be impossible
for me to argue with L.P. upstream.
My personal opinion is that the switch to meson was done too early, at
least 14.x could have used autotools and less meson patches.

But if upstream deliberately breaks compatibility there isn't much we
can do, maybe overpatching. sigh...

Cheers
A.A.
> >
> > Cheers
> > A.A.
> >
> >
> >
> > 
> >