Re: [PATCH RFC 1/4] firmware: Add the support for ZSTD-compressed firmware files

[Greg Kroah-Hartman]

On Wed, Feb 17, 2021 at 02:34:34PM +0100, Takashi Iwai wrote:
> On Wed, 17 Feb 2021 14:24:19 +0100,
> Luis Chamberlain wrote:
> > 
> > On Wed, Jan 27, 2021 at 04:49:36PM +0100, Takashi Iwai wrote:
> > > Due to the popular demands on ZSTD, here is a patch to add a support
> > > of ZSTD-compressed firmware files via the direct firmware loader.
> > > It's just like XZ-compressed file support, providing a decompressor
> > > with ZSTD.  Since ZSTD API can give the decompression size beforehand,
> > > the code is even simpler than XZ.
> > > 
> > > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
> > 
> > It also occurs to me that having a simple like #define HAVE_FIRMWARE_COMPRESS_ZSTD
> > on include/linux/firmware.h would enable userspace to be aware (if they
> > have kernel sources) to determine if the kernels supports this format.
> 
> Extending that idea, we might want to have a sysfs entry showing the
> supported formats instead?  This will allow to judge dynamically.

What could userspace do with that information?