[alsa-devel] [PATCH] Prefer kernel-versioned firmware directory.

Eliot Blennerhassett linux at audioscience.com
Thu Aug 18 23:57:05 CEST 2011

On 18/08/11 22:12, Takashi Iwai wrote:
>> From: Eliot Blennerhassett <eblennerhassett at audioscience.com>
>> Different kernel versions may have different driver versions installed,
>> which in turn require different firmware versions.
>> If /lib/firmware/$(uname -r) exists, use it in preference to the
>> generic /lib/firmware.
> It's no good idea.  The installation of the firmware has nothing to
> do with the running kernel version.  

But running version of the kernel module may depend on a particular
firmware version.

> The firmware in kernel-tree may
> be installed in the kernel-version specific directory, but it's
> basically not for external firmware.

External modules are not renamed, they are put in a kernel-versioned
directory, so why not the firmware that they need?

On this ubuntu installation, there is all sorts of firmware in
/lib/firmware/$(uname -r) and in /lib/firmare
Some files are duplicated in these locations, some aren't.

The former is searched before the latter when firmware is requested.
Now, if the system has installed firmware in a versioned directory, and
the someone 'updates' from alsa-firmware, they won't get the expected
result because the old firmware will be used in preference to the new.

> In principle, if a firmware is 
> compatible, you must rename it, e.g.
> with a version suffix, etc.  Or, if a firmware is backward compatible,
> we may keep using the same name.


Eliot Blennerhassett
AudioScience Inc.

More information about the Alsa-devel mailing list