how to signal an app from video miniport driver?

Hi

I have a video miniport driver and i want to signal my application
when somethign interesting happens inside that driver.
What i want to do is sort of what in pure WDM land would be said to be
as : "open the driver in asynchronous mode , and send an ioctl from
app to the driver and inside the driver do not call IoCompleteRequest
UNTIL sometihng interesting happens . In the aplication , keep waiting
on the event associated with the particular asynchronous call."

Now the problem following a similar approach in case of vidoe miniport
driver is that videoport.sys manages a strictly synchronously
serialized interface with all video miniport drivers where at the most
ONE VRP can be outstanding at any given time with a video miniport
driver.

How can i manage to solve this problem ? Should i manage it through
EVENT objects shared between user and kernel mode , and by passing the
address of the user mode EVENT object to my driver in the call to
EngDeviceIoControl ?

what would be the best approach here

thanks in advance
regards
Taha

M
Tue Jan 11 13:18:24 CST 2005

resending and widening the audience in the hope of some advice


M Taha Masood wrote:
> Hi
>
> I have a video miniport driver and i want to signal my application
> when somethign interesting happens inside that driver.
> What i want to do is sort of what in pure WDM land would be said to
be
> as : "open the driver in asynchronous mode , and send an ioctl from
> app to the driver and inside the driver do not call IoCompleteRequest
> UNTIL sometihng interesting happens . In the aplication , keep
waiting
> on the event associated with the particular asynchronous call."
>
> Now the problem following a similar approach in case of vidoe
miniport
> driver is that videoport.sys manages a strictly synchronously
> serialized interface with all video miniport drivers where at the
most
> ONE VRP can be outstanding at any given time with a video miniport
> driver.
>
> How can i manage to solve this problem ? Should i manage it through
> EVENT objects shared between user and kernel mode , and by passing
the
> address of the user mode EVENT object to my driver in the call to
> EngDeviceIoControl ?
>
> what would be the best approach here
>
> thanks in advance
> regards
> Taha

Calvin
Tue Jan 11 14:35:53 CST 2005

> How can i manage to solve this problem ? Should i manage it through
> EVENT objects shared between user and kernel mode , and by passing the
> address of the user mode EVENT object to my driver in the call to
> EngDeviceIoControl ?

You send the event handle to your display driver through an escape call. The
display driver then send an IOCTL to the miniport with EngDeviceIoControl.

> what would be the best approach here
Shared event is the easiest one. The drawback is you have to make another
escape to get any data (if any) associated with the event.

good luck!
--
Calvin Guan Software Engineer/Radeon NT Drivers
ATI Technologies Inc. Markham ON, Canada www.ati.com
No matter how many fish in the sea it'd be so empty without me - Without Me,
Eminem

M
Fri Jan 14 14:33:24 CST 2005

>
> > what would be the best approach here
> Shared event is the easiest one. The drawback is you have to make
another
> escape to get any data (if any) associated with the event.

Shared event solves my problem , but just out of curiosity , what other
approaches could have helped in this scenario

thanks and regards
Taha