[wdmaudiodev] Re: WaveRT MiniportDriver receiving IRP_MJ_CREATE in D3
- From: Surabhi Ghaisas <ghaisas.surabhi@xxxxxxxxx>
- To: wdmaudiodev@xxxxxxxxxxxxx
- Date: Wed, 23 Jul 2014 22:04:38 +0530
Thanks Mathew. I don't want to opt out of idle power management. When i
receive the IRP in driver whilethe driver is in D3 , I just want to have
some way to notify portclass and bring it back to D0 before proceeding with
IRP processing.
I used API "PcRequestNewPowerState(_pDeviceObject, PowerDeviceD0)" to bring
system to D0. After making this call I am doing timed wait for system to
enter D0. Driver proceeds with IRP processing only if system has entered D0
otherwise return failure. In my initial testing this method seems to work.
However i am not sure if this is the best solution for this problem.
regards,
Surabhi
On Wed, Jul 23, 2014 at 9:38 PM, Matthew van Eerde <
Matthew.van.Eerde@xxxxxxxxxxxxx> wrote:
> From a Windows developer:
>
>
>
> [T]he driver should not directly ask for a power D0/D3 IRP. Since these
> I/Os are not going through the portcls, they can disable Idle management,
> this would bring/keep the device in D0. Note that the API in portcls to
> disable idle management is not referenced counted, this means if they have
> multiple threads calling this API, the end result is unknown. If multiple
> threads are involved, they should serialize them and keep a ref count on
> when to turn on/off idle management
>
>
>
> […]
>
>
>
> Take a look at the SetIdlePowerManagement in
> http://msdn.microsoft.com/en-us/library/windows/hardware/ff536844(v=vs.85).aspx
>
> Note that they should also call the RegisterAdapterPowerManagement on that
> interface and support the IAdapterPowerManagement3.
>
>
>
> *From:* wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:
> wdmaudiodev-bounce@xxxxxxxxxxxxx] *On Behalf Of *Surabhi Ghaisas
> *Sent:* Tuesday, July 22, 2014 9:03 PM
> *To:* wdmaudiodev@xxxxxxxxxxxxx
> *Subject:* [wdmaudiodev] Re: WaveRT MiniportDriver receiving
> IRP_MJ_CREATE in D3
>
>
>
> Thanks Tim. Yes, my device needs to be in D0 for IRP processing.
>
>
>
> On Tue, Jul 22, 2014 at 10:36 PM, Tim Roberts <timr@xxxxxxxxx> wrote:
>
> Surabhi Ghaisas wrote:
> >
> > In WaveRT miniport driver I am exposing one device interface for use
> > by custom application by means of IoRegisterDeviceInterface. I want to
> > handle the IRPs that come for this interface in miniport driver
> > itself. For the same I have registered my own handlers for
> > IRP_MJ_CREATE and IRP_MJ_DEVICE_CONTROL.
> >
> > What I am observing is when there is no activity for my device my
> > driver enters D3 state as expected. After which when I launch my
> > custom application I receive calls to IRP_MJ_CREATE and then
> > IRP_MJ_DEVICE_CONTROL for registered interface as expected but all
> > this time driver state remains D3. I do not get a call to change
> > driver state to D0 before receiving these IRP calls. Is this expected
> > behaviour?
>
> Yes. It is up to the driver to decide when the device has to power up.
> For KS requests, the port driver has that knowledge. When you bypass
> the port driver, you have to do it.
>
> By the way, you have opened a real can of worms here. There are a large
> number of players involved (KS, Port class, Miniport, Bus), and each one
> of them thinks they own a piece of the power management pie.
>
> I'm a little surprised your device goes into D3. I didn't know the
> WaveRT port driver would do that.
>
>
>
> > Should miniport driver make call to PoSetPowerState for IRPs that are
> > not passed on portclass?
>
> Do your IRPs require the device to be in D0? If so, then you need to
> send an IRP_MJ_POWER with IRP_MN_SET_POWER. One of the existing drivers
> will call PoSetPowerState. I don't have any clue whether this will
> actually work. The port driver thinks it is managing the power policy.
>
> --
> Tim Roberts, timr@xxxxxxxxx
> Providenza & Boekelheide, Inc.
>
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