> -----Original Message-----
> From: Mark Brown <broonie@xxxxxxxxxx>
> Sent: Friday, October 2, 2020 4:20 AM
> To: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Cc: Ertman, David M <david.m.ertman@xxxxxxxxx>; Greg KH
> <gregkh@xxxxxxxxxxxxxxxxxxx>; alsa-devel@xxxxxxxxxxxxxxxx;
> tiwai@xxxxxxx; pierre-louis.bossart@xxxxxxxxxxxxxxx; Sridharan, Ranjani
> <ranjani.sridharan@xxxxxxxxx>; parav@xxxxxxxxxx
> Subject: Re: [PATCH 0/6] Ancillary bus implementation and SOF multi-client
> support
>
> On Thu, Oct 01, 2020 at 09:47:40PM -0300, Jason Gunthorpe wrote:
> > On Thu, Oct 01, 2020 at 09:17:18PM +0100, Mark Brown wrote:
>
> > Instead of making ancillary bus giant, it might be interesting to use
> > a library technique to avoid the code duplication you are talking
> > about, eg
>
> > struct my_ancillary_data {
> > struct ancillary_device adev;
> > struct ancillary_resource resources;
> > }
>
> > Then each user can access the facets they need.
>
> The way most of this stuff works already it's not a table in the device
> itself, it's an array of resources with type information. Your second
> struct there is presumably just going to be the pointer and size
> information which you *could* split out but I'm really not sure what
> you're buying there.
>
> The interesting bit isn't really the data in the devices themselves,
> it's the code that allows devices to just supply a data table and have
> things mapped through to their child devices. That isn't particularly
> complex either, but it's still worth avoiding having lots of copies of
> it. *None* of this bus stuff is hugely complex but we still don't want
> each device with children having to open code it all when they could
> just do something data driven.
Would you recommend adding two elements to the ancillary_device like:
void *ancillary_data;
u32 ancildata_size;
like the platform_device uses?
-DaveE
