Re: [linux-pm] potential pitfall? changing configuration while PC in hibernate (fwd)

Re: [linux-pm] potential pitfall? changing configuration while PC in hibernate (fwd)

[Michal Semler]

Hi!

It is real stupid, that Linux kernel freezes when simply during hibernate I 
change Bluetooth dongle to USB mouse in my USB port.

And it is not uncommon problem - I have BT dongle that starts in HID proxy 
mode and then I switch it to HCI mode. So I hibernate with BT dongle and 
after hibernate Linux only reads image from Swap and then freezes! :( Problem 
is, that It delete image from swap imeditially after reading it, so when I 
tried is simply with USB mouse (hibernate without it and plug it when 
notebook was switched off) it doesn't read it from swap ever and I lost all 
my memory :(

I can do nothing with this behavior of my dongle and there is no known way how 
to switch it back to HID-proxy mode before hibernate (Marcel correct me if I 
am wrong) - CSR based dongle D-Link with Apple firmware.

Windows knows it and doesn't have problem with it for 5 years! :)

Laptop is all Intel based, kernel 2.6.11.5-vanilla, gcc 3.4.3, Debian testing

Michal


> ----- Forwarded message from David Brownell <david-b@pacbell.net> -----
>
> X-Original-To: pavel@atrey.karlin.mff.cuni.cz
> To: linux-pm@lists.osdl.org
> Subject: Re: [linux-pm] potential pitfall? changing configuration while PC
> in hibernate Cc: Pavel Machek <pavel@ucw.cz>, Arioch <the_Arioch@nm.ru>
> X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on
>  atrey.karlin.mff.cuni.cz
> X-Spam-Level: *
> X-Spam-Status: No, score=1.8 required=5.0 tests=DNS_FROM_RFC_ABUSE,
>  DNS_FROM_RFC_POST autolearn=no version=3.0.2
> X-CRM114-Status: Good  ( pR: 18.5243 )
>
> On Monday 21 March 2005 1:52 am, Pavel Machek wrote:
> > On Po 21-03-05 11:02:04, Arioch wrote:
> > > I wonder, if hardware configuration asked for changes when resuming
> > > from hibernate ?
> >
> > Current position is "don't do this". You *will* be able to recover by
> > passing noresume, but if you change hw configuration, it may crash&burn.
>
> That may be Pavel's position, but USB-wise we absolutely consider
> it a bug if Linux misbehaves in the face of routine actions like
> unplugging a device during suspend (or plugging in a new one).
> Regardless of "noresume" etc.
>
> I'd say that's true for all hotpluggable busses, in fact, but I
> rarely submit patches for non-USB ones like PCMCIA or CardBus.
>
> - Dave
>
>
> ----- End forwarded message -----

-- 
S pozdravem

Michal Semler

Re: [linux-pm] potential pitfall? changing configuration while PC in hibernate (fwd)

[Andrew Morton]

Michal Semler <cijoml@volny.cz> wrote:
>
> It is real stupid, that Linux kernel freezes when simply during hibernate I 
> change Bluetooth dongle to USB mouse in my USB port.
> 
> And it is not uncommon problem - I have BT dongle that starts in HID proxy 
> mode and then I switch it to HCI mode. So I hibernate with BT dongle and 
> after hibernate Linux only reads image from Swap and then freezes! :( Problem 
> is, that It delete image from swap imeditially after reading it, so when I 
> tried is simply with USB mouse (hibernate without it and plug it when 
> notebook was switched off) it doesn't read it from swap ever and I lost all 
> my memory :(
> 
> I can do nothing with this behavior of my dongle and there is no known way how 
> to switch it back to HID-proxy mode before hibernate (Marcel correct me if I 
> am wrong) - CSR based dongle D-Link with Apple firmware.
> 
> Windows knows it and doesn't have problem with it for 5 years! :)
> 
> Laptop is all Intel based, kernel 2.6.11.5-vanilla, gcc 3.4.3, Debian testing

Can you please retest 2.6.12-rc5, see if this bug is still there?

Thanks.

Re: [linux-usb-devel] Re: [linux-pm] potential pitfall? changing configuration while PC in hibernate (fwd)

[David Brownell]

On Wednesday 25 May 2005 4:47 pm, Andrew Morton wrote:
> Michal Semler <cijoml@volny.cz> wrote:
> >
> > It is real stupid, that Linux kernel freezes when simply during hibernate I 
> > change Bluetooth dongle to USB mouse in my USB port.

That is, you unplug the dongle -- breaking the USB power session -- and then
plug in a mouse?  And the kernel does something other than disconnecting the
dongle, and then enumerate a new mouse?  That'd be a bug.  Somewhere.  It'd
probably help a lot if the bluetooth USB driver had a suspend() method.

It's not clear to me what you mean by "hibernate".  If that's an "everything
powered off" pseudo-suspend state, then the dongle should always be getting
disconnected, and USB always re-enumerated by Linux.  Only "real suspend"
states, like suspend-to-RAM, can normally maintain USB power sessions.  And
even then, the device drivers need to be prepared to maintain them ... and
do things like stop active I/O requests, and resume them later.

You said this was an all-Intel system.  So which host controller driver is
in use here ... UHCI?  EHCI?  With RC5 and CONFIG_USB_DEBUG, what do the
USB debug messages say is happening?  Does CONFIG_USB_SUSPEND change things?
Try this with purely modular USB for now.

- Dave