Re: hda-compiler, was: hda-verb, hda-analyzer, hda-emu and codecgraph

[Takashi Iwai <tiwai@suse.de>]

At Tue, 27 Jul 2010 17:33:32 +0200,
David Henningsson wrote:
> 
> 2010-07-27 16:57, Jaroslav Kysela skrev:
> > A little off topic: hda-compiler . I'm playing with an idea to have the
> > hda-intel driver behaviour description (patches) in a firmware file.
> 
> There seem to be more than one thought in that area. Recently there has
> been some discussion (at least on Ubuntu Developer Summit) whether the
> device-tree[1] structure could be used in this area as well.
> Since we would then have separate device-tree files, we could update
> them independent of the kernel.

Did it come from Andy?  I've heard the idea to use OF from Grant in
the last year, and yes, this is feasible.  But I'm not sure how much
gain we'd get in the end.

For new devices, except for a few ones like AD or Conexant, we usually
write the generic tree parser so that BIOS information can be parsed
dynamically.  If BIOS information is broken or insufficient, we can
add some hints for correction, via sysfs for debugging or statically
in the code for production.  And the rest of the problem is very
specific to devices, and requires often some quirks in the parser
itself.  So, in this scenario, there is little room OF can help.
We'd like rather to avoid the static data, no matter in which form.

Meanwhile, the deployment of OF can be helpful if we move the whole
parser stuff to the user-space and push the parsed/compiled tree info
into the kernel (i.e. "firmware").  In such a case, OF representation
can be more flexible; and the kernel has already the infrastructure.


thanks,

Takashi