[REGRESSION] bcm2835-audio fails to register on vchiq-bus in monolithic kernels since 6.19 (VCHIQ destaging?)

[Jai Luthra]

Hi Martin, Thorsten,

Quoting Thorsten Leemhuis (2026-10-12 18:53:13)
> On 9/21/26 12:07, Martin Wetterwald wrote:
> 
> > After moving from 6.18.52 to 6.19 (still present in 7.2.6), the bcm2835
> > Headphones sound card no longer appears on my Raspberry Pi 3 Model B Rev 1.2
> > (arm64). 6.18.52 works with the exact same userspace.
> > [...]
> > My suspect is this commit:
> > 
> >   aa125180c673881f88b528600b57865dc158b3a7
> >   ("platform/raspberrypi: Destage VCHIQ interface")
> > 
> > I could not bisect to a single commit,
> 
> Hmm, no answer, so it seems nobody really cares. A bisection might help.
> Or at least validating your suspicion, hence: why can't you check the
> parent of aa125180c6738 and aa125180c6738 itself? Or at least the range
> with that commit in it? And is latest 7.3-rc still broken?
> 

Sorry, this got lost in my inbox last month. It's likely my series that 
destaged VCHIQ broke the ordering as Martin suspects. I always tested with 
modules enabled so didn't encounter this issue.

I'll look into how we can ensure the VCHIQ bus gets registered before 
peripheral drivers (like audio here) when CONFIG_MODULES=n. If someone 
already knows what to do, pointers are appreciated :-)

> Ciao, Thorsten

Thanks,
Jai