[alsa-devel] [PATCH] ucm: add cset-tlv command

[Takashi Iwai]

On Wed, 23 Mar 2016 10:44:31 +0100,
Hsin-yu Chao wrote:
> 
> On Wed, Mar 23, 2016 at 5:21 PM, Takashi Iwai <tiwai at suse.de> wrote:
> > On Wed, 23 Mar 2016 10:15:21 +0100,
> > Hsin-yu Chao wrote:
> >>
> >> On Tue, Mar 22, 2016 at 7:48 PM, Takashi Iwai <tiwai at suse.de> wrote:
> >> > On Tue, 22 Mar 2016 10:10:34 +0100,
> >> > Hsin-Yu Chao wrote:
> >> >>
> >> >> This patch enables UCM to set a file in TLV format to kcontrol by:
> >> >> cset-tlv "name='<kcontrol-name>' <path-to-file>"
> >> >> This new 'cset-tlv' command will be used to write audio DSP to
> >> >> specific alsa control, where the driver expectes a file in TLV
> >> >> format.
> >> >>
> >> >> Signed-off-by: Hsin-Yu Chao <hychao at chromium.org>
> >> >
> >> > One problem in this approach is that the provided TLV data file isn't
> >> > portable.  Since we deal TLV as int arrays, it's endian-sensitive.
> >> > At least, some endian check would be needed.
> >> Thanks for the review. I think by extracting the length attribute (i.e
> >> tlv[1]) and compare it with the file size is sufficient here, since
> >> there is no way to figure out the endianness of the binary file passed
> >> in.
> >
> > Yeah, that should be good enough.
> >
> >
> >> Also I agree that additional check for crazy large or small file is
> >> necessary. According to the dsp files I test with, I'll set the tlv
> >> file size limit to between 8 bytes and 1MB.
> >
> > I guess the size will grow quickly in near future, so it'd be safer to
> > take a bit bigger.
> >
> How about using 16MB as upper limit?
> DSP file larger than that would take 1 second or more to load through USB 2.0.

Yes, 16MB should be big enough.


thanks,

Takashi