[lkml]   [2012]   [Jan]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: loading firmware while usermodehelper disabled.
On Sun, 1 Jan 2012 22:27:56 +0100
Oliver Neukum <> 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.

 \ /
  Last update: 2012-01-01 22:41    [W:0.132 / U:1.496 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site