Hi,
Thank you for your response.
Unfortunately the hardware is not under my control so
I won't be able to fix the real problem.
But the workaround you suggested worked like a charm.
regards,
filip-
> ------------------------------
>
> Message: 2
> Date: Tue, 27 Feb 2007 08:01:56 -0800
> From: David Ferguson <email@hidden>
> Subject: Re: Expresscard troubled sleep
> To: USB List at Apple <email@hidden>
> Message-ID: <email@hidden>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
> If you have any control over the hardware for this
> ExpressCard, then request that the USB power be connected to
> the 3.3VAUX input. Per the ExpressCard spec, the 3.3V power
> rail goes away when the machine
> sleeps, but the 3.3VAUX remains powered. USB requires that devices
> support suspend, and the only way to do that without
> disconnecting is
> to use the 3.3VAUX power. Since your USB function requires more
> power than 3.3VAUX allows, I think you should connect 3.3V
> and 3.3VAUX together on your card. When suspended you can't
> draw more power than the 3.3VAUX spec, but this is more than
> the USB spec for suspend anyway.
>
> We are about ready to release a technote on this very subject.
>
> If you don't have any influence on the hardware, then there is a
> workaround. If your device is a composite device (device class 0,
> subclass 0), then you can add a property that will configure
> the system to not allow the system to wake on card-unplug while
> sleeping. If your device is not composite, then you'll have to do
> what the composite driver does. This info is in the tech
> note, contact DTS for details.
>
> David Ferguson
> USB Software Team
> Apple
>
> On Feb 27, 2007, at 2:52 AM, Filip Aben wrote:
>
> > Hello,
> >
> > I'm currently writing a driver for an Expresscard usb
> device and ran
> > into the following problem:
> >
> > When the Macbook goes to sleep, the expresscard takes away the 3.3V
> > power and expects the card to sleep on the 3.3Vaux.
> However, this card
> > can't run at all on the 3.3Vaux and thus causes a usb disconnect,
> > which in turn causes the macbook to wake up again.
> >
> > So when I close the Macbook lid, the laptop starts a neverending
> > sleep-wake cycle.
> > I tried to use PM in my USB driver to specify only an 'on' and 'off'
> > state, but doesn't make a difference.
> > ( Didn't really expect that to work since expresscard usb
> devices are
> > essentially self-powered devices )
> >
> > So my question is: is there any way to control the
> expresscard power
> > management from within my driver?
> > Preferably I'd like to take away the device power entirely
> when system
> > goes to sleep.
> >
> > Any help greatly appreciated.
> >
> > regards,
> >
> > Filip Aben
> > _______________________________________________
>
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