[systemd-devel] Problems loading firmware using built-in drivers with kernels that use initramfs.

[Lennart Poettering]

On Mon, 24.08.15 21:50, Liam Girdwood (liam.r.girdwood at linux.intel.com) wrote:

> Currently firmware loading with built-in drivers is failing on systems
> that mount an initramfs before the root FS is mounted (that contains the
> firmware file). Modular drivers work fine.
> 
> Keyon (Jie, Yang) has done some testing with the Intel audio DSP driver
> and found that the built-in firmware loading only works if the firmware
> is included as part of the initramfs. The same has been seen with other
> Intel drivers that use firmware.
> 
> In this case it looks like userspace (udevd ?) is checking initramfs for
> pending firmware requests and returning not found if it cant find the
> files, but it's not re-checking for any pending firmware requests once
> the real FS is mounted. Is it possible to have udevd re-check the
> pending firmware requests after the real FS is mounted ?

With current kernel versions (3.7 and newer) userspace in general and
udev in particular are not involved with firmware loading anymore. In
fact support for firmware loading has been removed with systemd 217,
thus making 3.7 the minimal kernel version we support.

Lennart

-- 
Lennart Poettering, Red Hat