Multiple named filters

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Hello:

I have upper filter above "serenum".
In Filter.AddDevice(...) I created named object "NamedFilter_1".
I can open/close and read/write to "NamedFilter_1"
from user-mode appl


In Filter.DriverEntry(...) I created named object "NamedFilter_2".

Using the same user-mode appl I can open/close this object.

But when I try to write to "NamedFilter_2" IRP_MJ_WRITE arrives with
stack->Parameters.Write.Length = 0 and
Irp->AssociatedIrp.SystemBuffer = NULL


Thank you,
dave
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Re: Multiple named filters by Calvin

Calvin
Tue Feb 15 20:03:17 CST 2005

Make sure you have setup the device flags for NamedFilter_2 correctly. If
you want to use buffered IO, you need to set the flag DO_BUFFERED_IO.

--
Calvin Guan Software Engineer/Radeon NT Drivers
ATI Technologies Inc. Markham ON, Canada www.ati.com

"dave" <dave@discussions.microsoft.com> wrote in message
news:55DDCBF1-DBA4-424E-8DDA-6E41A13DB4B5@microsoft.com...
>
> Hello:
>
> I have upper filter above "serenum".
> In Filter.AddDevice(...) I created named object "NamedFilter_1".
> I can open/close and read/write to "NamedFilter_1"
> from user-mode appl
>
>
> In Filter.DriverEntry(...) I created named object "NamedFilter_2".
>
> Using the same user-mode appl I can open/close this object.
>
> But when I try to write to "NamedFilter_2" IRP_MJ_WRITE arrives with
> stack->Parameters.Write.Length = 0 and
> Irp->AssociatedIrp.SystemBuffer = NULL
>
>
> Thank you,
> dave
>


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Re: Multiple named filters by dave

dave
Wed Feb 16 11:41:20 CST 2005

Thank you,

dave

"Calvin Guan" wrote:

> Make sure you have setup the device flags for NamedFilter_2 correctly. If
> you want to use buffered IO, you need to set the flag DO_BUFFERED_IO.
>
> --
> Calvin Guan Software Engineer/Radeon NT Drivers
> ATI Technologies Inc. Markham ON, Canada www.ati.com
>
> "dave" <dave@discussions.microsoft.com> wrote in message
> news:55DDCBF1-DBA4-424E-8DDA-6E41A13DB4B5@microsoft.com...
> >
> > Hello:
> >
> > I have upper filter above "serenum".
> > In Filter.AddDevice(...) I created named object "NamedFilter_1".
> > I can open/close and read/write to "NamedFilter_1"
> > from user-mode appl
> >
> >
> > In Filter.DriverEntry(...) I created named object "NamedFilter_2".
> >
> > Using the same user-mode appl I can open/close this object.
> >
> > But when I try to write to "NamedFilter_2" IRP_MJ_WRITE arrives with
> > stack->Parameters.Write.Length = 0 and
> > Irp->AssociatedIrp.SystemBuffer = NULL
> >
> >
> > Thank you,
> > dave
> >
>
>
>
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