Re: Problems loading firmware using built-in drivers with kernels that use initramfs.

[Ming Lei <ming.lei@canonical.com>]

On Thu, Aug 27, 2015 at 2:07 AM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Wed, Aug 26, 2015 at 1:06 AM, Liam Girdwood
> <liam.r.girdwood@linux.intel.com> wrote:
>>
>> I think the options are to either :-
>>
>> 1) Don not support audio DSP drivers using topology data as built-in
>> drivers. Audio is not really a critical system required for booting
>> anyway.
>
> Yes, forcing it to be a module and not letting people compile it in by
> mistake (and then not have it work) is an option.
>
> That said, there are situations where people don't want to use
> modules. I used to eschew them for security reasons, for example - now
> I instead just do a one-time temporary key. But others may have other
> reasons to try to avoid modules.
>
>> 2) Create a default PCM for every driver that has topology data on the
>> assumption that every sound card will at least 1 PCM. This PCM can then
>> be re-configured when the FW is loaded.
>
> That would seem to be the better option if it is reasonably implementable.
>
> Of course, some kind of timer-based retry (limited *somehow*) of the
> fw loading could work too, but smells really really hacky.

Yeah, years ago, we discussed to use -EPROBE_DEFER for the situation,
which should be one kind of fix, but looks there were objections at that time.

thanks,