[Mesa-dev] Android: apps crashed on Intel Gen9 GPU

[Pohjolainen, Topi]

On Thu, May 12, 2016 at 12:25:25AM +0800, Chih-Wei Huang wrote:
> Testing android-x86 with mesa 11.2.2,
> I found the Google Play crashed forever on
> a device with Intel Gen9 GPU (e.g., Skylake).
> 
> After analyzing, the i965 driver seems to assume
> irb->mt is not null. For example in
> brw_meta_fast_clear of brw_meta_fast_clear.c:
> 
>       struct intel_renderbuffer *irb = intel_renderbuffer(rb);
>       ...
>       if (brw->gen >= 9 &&
>           brw_format_for_mesa_format(irb->mt->format) !=
>                                                     ^^^^^^^^^ => crashing
>           brw->render_target_format[irb->mt->format])
>          clear_type = REP_CLEAR;
> 
> If I added null checking to irb->mt, it fixes this crashing.
> However, the app still crashed at other place that
> accesses irb->mt similarly.
> (brw_draw.c line 399, gen8_surface_state.c line 432, etc)
> 
> Please comment how to fix it correctly.
> Why irb->mt is null but the code assumes it's not?

As far as I understand something has gone wrong before - having an
intel_renderbuffer without a miptree shouldn't be a reachable state at all.