Re: Problems loading firmware using built-in drivers with kernels that use initramfs.

From: Arend van Spriel
Date: Sat Oct 17 2015 - 04:32:48 EST


On 10/16/2015 09:35 PM, Luis R. Rodriguez wrote:
On Thu, Sep 03, 2015 at 10:33:51AM -0700, Dmitry Torokhov wrote:
On Thu, Sep 3, 2015 at 10:23 AM, Arend van Spriel <arend@xxxxxxxxxxxx> wrote:
On 09/03/2015 01:46 AM, Luis R. Rodriguez wrote:

On Wed, Sep 2, 2015 at 4:29 PM, Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:

On Wed, Sep 2, 2015 at 4:22 PM, Luis R. Rodriguez <mcgrof@xxxxxxxx>
wrote:
IMHO its just as hacky as using -EPROBE_DEFER too, but its at least
preemptively hacky. Sadly I can't think of clear and clever way for the
kernel
to know when firmware will be ready either... Would userspace know?
Should the
kernel learn this from userspace ?


Yes. Given only userspace knows when firmware is available (I could
have it on a separate device and mount it at some time). So maybe
userpsace should simply try and scan busses for unbound devices and
tell them to re-probe when it decides that firmware is finally
available.


OK, the folks wanting this mechanism can implement it then. Short of
that we only have hacks.


So what does "userspace knows when firmware is available" mean here. The
specific firmware file the driver wants or the collection of firmware files
which may or may not have the specific firmware file the driver wants. I
assume the latter and re-probe will fail as expected.

Right, the latter.

Arend, curious are you working on this? Me and Julia did some hunting and
have found quite a bit of users that could use this. I'll provide results
in another thread but figured I'd follow up to see if anyone is working
to address this. Otherwise we just have hacks for now.

Not doing much else than diaper changes these days. Seems to me based on the above that from kernel perspective we can not do much when firmware mounts are controlled by user-space.

Regards,
Arend

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