USB power management

NTDEV
1

I am use the DriverWorks package of Numega to write a USB driver for a
Braille output device. The driver basically works but I have a problem with
some chipsets (Ali) under Windows XP. The device does not resume when the PC
is resuming from suspend.
From several sources I have determined that I have to implement some power
management functionality for suspension and resume. The default handling of
DriverWorks seems not te be enough.
Does anyone have any examples or any information on how to implement this.

Greetings,
C.A. van Strien
R&D Engineer
Tieman Development BV

2

Hello,

I am use the DriverWorks package of Numega to write a USB driver for a
Braille output device. The driver basically works but I have a problem with
some chipsets (Ali) under Windows XP. The device does not resume when the PC
is resuming from suspend.
From several sources I have determined that I have to implement some power
management functionality for suspension and resume. The default handling of
DriverWorks seems not te be enough.

I mean this is enough. For devices with no power I have made my
special hack and in OnPowerUp() I reset my USB devices with
IOCTL_INTERNAL_USB_CYCLE_PORT.

elli

3

> Subject: Re: USB power management

From: Mathias Ellinger
> Date: Tue, 19 Mar 2002 13:35:26 +0100
>
> Hello,
>
> >I am use the DriverWorks package of Numega to write a USB
> driver for a
> >Braille output device. The driver basically works but I have
> a problem with
> >some chipsets (Ali) under Windows XP. The device does not
> resume when the PC
> >is resuming from suspend.
> >From several sources I have determined that I have to
> implement some power
> >management functionality for suspension and resume. The
> default handling of
> >DriverWorks seems not te be enough.
>
> I mean this is enough. For devices with no power I have made my
> special hack and in OnPowerUp() I reset my USB devices with
> IOCTL_INTERNAL_USB_CYCLE_PORT.
>
> elli
>

Hello Mathias,
Thanks for your reply. Maybe I should have stated that I use a failry old,
acc. to Numega, version of DriverWorks (2.1). It appears that there is
simply no power management in this version of the library. So there is also
no OnPowerUp().
From where do you send the IOCTL_INTERNAL_USB_CYCLE_PORT, and where to?

Please include my e-mail address in your reply too because I receive the
digest version of this list.

Regards,
Corand