On Wed, 2019-04-03 at 16:49 +0200, Guennadi Liakhovetski wrote:
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?
This size can be anything, even 0 is valid. Look at the extended boot data sent by the FW at boot in platform.c (e.g. src/platform/baytrail/platform.c)
Liam