[PATCH RFC 00/11] staging: vc04_services: Improve driver load/unload

[Peter Robinson]

Hi Stefan,

> > > > I get difference results with 5.0-rc1 but neither of the above apps
> > > > work either, will follow up based on the rest of the thread there.
> > > >
> > >
> > > My first step with Raspbian is to enable the Camera interface which results into an appending of the following lines to config.txt:
> > >
> > > start_x=1
> > > gpu_mem=128
> > >
> > > AFAIK a smaller value for gpu_mem wont work. Please provide your settings which results in this crash.
> >
> > start_x=1
> > gpu_mem=64
>
> even with those settings i'm getting a picture in qv4l2 (v1.12.3) and no crash.
>
> According to dmesg i also have 64M reserved for CMA. How many do you have?

I have 192Mb of CMA with LXDE, the vc4 driver uses CMA rather than the
gpu_mem via the firmware so that's what we set it to (and to 256Mb for
GNOME)

> Does your qc4l2 make use of OpenGL (not in my case)?

Yes, mine does. The crash with qv4l2 was only when I tried Cheese
first, if I reboot and just use qv4l2 it works fine when configured
with 128Mb without any crash. Which display driver are you using? Are
you using vc4 or the proprietary closed one? With vc4 using cma rather
than gpu_mem I wonder if we can reduce the amount needed there, but in
the interim I've at least now got picture output when using purely
qv4l2 and a reserve of 128Mb

I'm not sure quite what gstreamer1/cheese is doing to cause that crash.

Peter