[wdmaudiodev] Re: AVStream and WDF
- From: KS <wakeup1504@xxxxxxxxx>
- To: wdmaudiodev@xxxxxxxxxxxxx
- Date: Sun, 25 Oct 2009 12:20:11 +0800
Hi Eliyas,
Just another question. Is KMDF driver supported by default in WinXP, Vista
and Windows 7? Or do we need to install some service pack or components (eg.
.NET framework needed for .NET) before KMDF driver can be used? What happen
when the KMDF driver is installed in an OS that does not have all the
necessary components required?
Thanks
KS
On Sun, Oct 25, 2009 at 8:22 AM, Eliyas Yakub <eliyasy@xxxxxxxxxxxxx> wrote:
> Yes if you want to use full capabilities of WDF then two driver model is
> best.
>
>
>
> Does anybody know whether AVSTREAM support selective suspend?
>
>
>
> *From:* wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:
> wdmaudiodev-bounce@xxxxxxxxxxxxx] *On Behalf Of *Sam Tertzakian
> *Sent:* Saturday, October 24, 2009 5:18 PM
>
> *To:* wdmaudiodev@xxxxxxxxxxxxx
> *Subject:* [wdmaudiodev] Re: AVStream and WDF
>
>
>
> Hi, Eliyas,
>
>
>
> Would you say it is true that if you want to use the full capabilities of
> WDF using a two driver model is best? I say this because your slide 30
> shows that many important features of WDF cannot be used in a single driver
> model.
>
>
>
> In the past I have written code such that a single AVStream driver could
> be used with both an underlying PCI bus or a USB bus. I used an underlying
> WDF or WDM driver to deal with the buffer transfer between the bus/card and
> host memory...then, I exposed a device interface that an AVStream driver
> used to expose the board as an AVStram device.
>
>
>
> In this way, I get full use of WDF for all the hardware stuff, but I only
> have to write the code that exposes the card to AVStream one time. If I want
> to add another bus type, then I can just write another underlying WDF driver
> for that bus and reuse the same AVStream layer without modification.
>
>
>
> *From:* wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:
> wdmaudiodev-bounce@xxxxxxxxxxxxx] *On Behalf Of *Eliyas Yakub
> *Sent:* Saturday, October 24, 2009 7:17 AM
> *To:* wdmaudiodev@xxxxxxxxxxxxx
> *Subject:* [wdmaudiodev] Re: AVStream and WDF
>
>
>
> Yes it’s possible to write AVStream driver with KMDF. You don’t need to
> have a filter driver. Please go through this presentation and let me know if
> you have question. Using KMDF to interface with the USB stack is the best
> way of doing it. Most NDIS miniport drivers for USB drivers are written
> using KMDF.
>
>
>
>
> http://download.microsoft.com/download/D/1/D/D1DD7745-426B-4CC3-A269-ABBBE427C0EF/DDE-T685_DDC08.pptx
>
>
>
> This model has been supported from version 1.0. Latest WDF version that was
> release with Win7 is 1.9 and you should use that.
>
>
>
> *From:* wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:
> wdmaudiodev-bounce@xxxxxxxxxxxxx] *On Behalf Of *KS
> *Sent:* Saturday, October 24, 2009 4:37 AM
> *To:* wdmaudiodev@xxxxxxxxxxxxx
> *Subject:* [wdmaudiodev] Re: AVStream and WDF
>
>
>
> Hi,
>
>
>
> While this is possible and would work, I think it would be something that
> would be considered as one of the last resort if there is no other way and
> the change must be made. This is something like asking Microsoft to split
> their usbaudio.sys driver, which is an AVStream driver, into 2 drivers so
> that it is WDF compilant and fulfill WLP requirement.
>
>
>
> I would hope that there should be some method that is less painful for
> those who have an existing AVStream driver that communicate with a usb
> device. (Or that the WLP requirement does not apply to usb drivers that are
> using AVStream framework)
>
>
>
>
>
> KS
>
>
>
>
> On Sat, Oct 24, 2009 at 7:17 PM, Sam Tertzakian <saekisam@xxxxxxxxx>
> wrote:
>
> You would write two drivers...a lower wdf driver that talks directly to the
> hardware as a generic wdf driver. Then you install an upper filter driver
> over the wdf driver that exposes the device as an avstream driver. Avstream
> driver then sends and receives data from the lower driver.
> ------------------------------
>
> *From: *KS <wakeup1504@xxxxxxxxx>
>
> *Date: *Sat, 24 Oct 2009 18:50:00 +0800
>
> *To: *<wdmaudiodev@xxxxxxxxxxxxx>
>
> *Subject: *[wdmaudiodev] AVStream and WDF
>
>
>
> Hi,
>
>
>
> Is it possible to write an AVStream driver using WDF? I posted this
> questions a few years back and the answer was no.
>
>
>
> There were some code snippets on using AVStream with WDF in the Winhec 2008
> presentation, and there is also some new WLP requirements for USB drivers to
> be WDF compilant. So does this mean that it is now possible to use AVStream
> with WDF (since many usb audio/video device would be using AVStream driver)?
> If this is true, is there any info on what is the minimum KMDF version that
> can support this, and any info on what can and what cannot be done with WDF
> for AVStream would be appreciated.
>
>
>
> Thanks
>
>
>
> KS
>
>
>
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