[Sound-open-firmware] can stream-box size be 0?

[Guennadi Liakhovetski]

On Wed, Apr 03, 2019 at 03:39:02PM +0100, Liam Girdwood wrote:
> On Wed, 2019-04-03 at 15:33 +0200, Guennadi Liakhovetski wrote:
> > Hi,
> > 
> > In kernel ipc.c I see "if (sdev->stream_box.size == 0)" checks at
> > exactly 4 locations, but all currently supported by SOF platforms set
> > the size to 0x200. Do we need those checks or can we safely assume, that
> > the size is never 0?
> 
> The size can depend on FW platform and how much space they allocate for mmap()
> stream position information. i.e. ALSA can read pipeline stream position stats
> directly from mailbox rather than via IPC.

Does that mean, that I misunderstood something? Could you point me out
to the code, that can set that size to anything other than 0x200, as
supplied by the firmware?

Thanks
Guennadi