[alsa-devel] [PATCH 1/1] hdsp: allow firmware loading from inside the kernel

[Takashi Iwai]

At Tue, 12 May 2009 09:41:36 +0200,
Raphaël Doursenaud wrote:
> 
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> Takashi Iwai a écrit :
> > At Tue, 12 May 2009 09:25:27 +0200,
> > Raphaël Doursenaud wrote:
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> >> Takashi Iwai a écrit :
> >>> At Tue, 12 May 2009 09:05:19 +0200,
> >>> Raphaël Doursenaud wrote:
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> >>>> Takashi Iwai a écrit :
> >>>>> At Tue, 12 May 2009 08:47:29 +0200,
> >>>>> Raphaël Doursenaud wrote:
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> >>>>>>
> >>>>>> Takashi Iwai a écrit :
> >>>>>>> At Tue, 12 May 2009 08:16:08 +0200,
> >>>>>>> Raphaël Doursenaud wrote:
> >>>>>>>> From: Raphaël Doursenaud <rdoursenaud at free.fr>
> >>>>>>>>
> >>>>>>>> Allow the use of  the FIRMWARE_IN_KERNEL option with hdsp cards and
> >>>>>>>> in-kernel driver.
> >>>>>>> Did it really work without problems?
> >>>>>>>
> >>>>>>>
> >>>>>>> Takashi
> >>>>>> Tested over the weekend with two multifaces in my DAW.
> >>>>>> Got no problem.
> >>>>> Interesting.
> >>>>> Did you build the firmware file into the kernel, or not?
> >>>>>
> >>>>>
> >>>>> Takashi
> >>>> Yes I built all hdsp fimware files (multiface_firmware.bin
> >>>> multiface_firmware_rev11.bin digiface_firmware.bin
> >>>> digiface_firmware_rev11.bin) into the kernel.
> >>>> It's the aim of this patch.
> >>> Well, the problem I'm concerned is that the driver can be compiled
> >>> in even if you have no built-in firmware.  And there is no restriction
> >>> or dependency check in Kconfig, so far.
> >>>
> >>> Could you test how the kernel behaves without the built-in firmware?
> >>> Does it hang or give any critical error?
> >>>
> >>>
> >>> thanks,
> >>>
> >>> Takashi
> >> Could you be more specific?
> >> I'm not sure to understand why it could be a problem.
> >> Do you think that if I set FIRMWARE_IN_KERNEL without compiling the
> >> firmware(s) in-kernel the request_firmware() will not resolve and cause
> >> an error?
> > 
> > Yes, exactly.
> > request_firmware() shall fail in that case likely after a long
> > time-out (unless you have the firmware files in initrd) because there
> > is really no file / data available at the time it's called.
> > And I'm not sure whether this could lead to a fatal operation error.
> > 
> > 
> > Takashi
> AFAIK this is handled in the code (from line 5080) and should lead to
> "Hammerfall-DSP: couldn't get firmware from userspace. try using hdsploader"

Yep, a fallback mechanism is found in hdsp driver itself.
But the driver probe hangs for too long time, and I'm just worried
about its influence on the whole kernel boot-up.

> I'm building a kernel to test that case.

Thanks.


Takashi