Re: loading firmware while usermodehelper disabled.

Michael Büsch
2012-01-01T21:39:32Z

On Sun, 1 Jan 2012 22:27:56 +0100
Oliver Neukum <oliver@neukum.org> wrote:

> Ideally usbcore would deal with such devices, but at present the USB layer
> is unable to cleanly resume devices that change their IDs during
> resume.
> Solving this would mean putting all firmware loaders into kernel space.
> And the mode switching logic as well.

I don't get it. Why would a device enter a state after resume, that it was not
in at _any_ time before the machine was suspended?

These change-id-on-bootstrap devices usually work like this,
as far as I know:

probe bootstrap device (switches hw to real device)
probe real device (firmware is loaded)
Suspend machine
Resume machine
usb detects that the device is "gone"
probe/resume bootstrap device (switches hw to real device)
probe/resume real device (No need to fetch fw from userspace. It's already cached)

What did I get wrong?

--
Greetings, Michael.