[wdmaudiodev] Re: question on DMUS UART
- From: "Philip Lukidis" <pagefault0x0@xxxxxxxxxxx>
- To: <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Tue, 17 Feb 2004 17:38:47 -0500
FWIW, I took a quick look at my old code. It appears that I did hold my
spinlock while calling PutMessage. This was a DpcLevel spin lock which
would not touch the IRQL. In any case, I should not have done this,
clearly. I'm not sure my old DMUS driver would work anymore for testing, as
my bus driver below it has changed a fair bit since I last tested this.
Philip Lukidis
----- Original Message -----
From: "Matt Gonzalez" <matt@xxxxxxxxxxxxx>
To: <wdmaudiodev@xxxxxxxxxxxxx>
Sent: Tuesday, February 17, 2004 3:02 PM
Subject: [wdmaudiodev] Re: question on DMUS UART
> For what it's worth, our PCI cards use a DMUS miniport for MIDI I/O. It
> works fine on dual processor 2000 & XP.
>
> I remember that there was a minor bug in the DDK sample with handling
> PutMessage, but that was for MIDI output. That was a few years ago; I
> don't remember the specifics. It's in the mailing list archive somewhere.
>
> Reading through my code, I did notice that I don't hold my spinlock
> during the call to PutMessage. That might make a difference.
>
> For what it's worth, here's the code. This is just a modified DDK
> sample, so I don't think I'm giving away any trade secrets.
>
> STDMETHODIMP_(NTSTATUS)
> CMiniportDMusStreamEcho::SourceEvtsToPort()
> {
> NTSTATUS ntStatus;
> ECHOSTATUS Status;
> DWORD dwMidiByte;
> LONGLONG llNewTimestamp,llLastTimestamp;
>
> ASSERT(KeGetCurrentIrql() == DISPATCH_LEVEL);
> //DOUT(DBG_PRINT, ("SourceEvtsToPort"));
>
> if (m_fCapture) // is capture running?
> {
> PDMUS_KERNEL_EVENT aDMKEvt,eventTail,eventHead;
>
> aDMKEvt = NULL;
> eventTail = NULL;
> eventHead = NULL;
> ntStatus = STATUS_SUCCESS;
> llLastTimestamp = 0;
>
> KeAcquireSpinLockAtDpcLevel(m_pMiniport->m_pSpinLock);
>
> do
> {
> //
> // Get the next MIDI byte
> //
> Status =
> m_pMiniport->m_pEG->ReadMidiByte(dwMidiByte,llNewTimestamp);
>
> if (ECHOSTATUS_OK == Status)
> {
> //
> // Get another event from the allocator if necessary
> //
> if ( (NULL == eventHead) ||
> (MAX_BYTES_PER_EVENT == aDMKEvt->cbEvent) ||
> (llNewTimestamp != llLastTimestamp) )
> {
> //
> // Get the new event & put it at the end of
> // the linked list of capture events
> //
> (void) m_AllocatorMXF->GetMessage(&aDMKEvt);
> if (!aDMKEvt)
> {
> DOUT(DBG_ERROR, ("SourceEvtsToPort can't
> allocate DMKEvt"));
> ntStatus = STATUS_INSUFFICIENT_RESOURCES;
> break;
> }
>
> // put this event at the end of the list
> aDMKEvt->pNextEvt = NULL;
> if (!eventHead)
> {
> eventHead = aDMKEvt;
> }
> else
> {
> eventTail = eventHead;
> while (eventTail->pNextEvt)
> {
> eventTail = eventTail->pNextEvt;
> }
> eventTail->pNextEvt = aDMKEvt;
> }
>
> aDMKEvt->cbEvent = 0;
> aDMKEvt->usChannelGroup = 1;
> aDMKEvt->usFlags = DMUS_KEF_EVENT_INCOMPLETE;
> aDMKEvt->ullPresTime100ns = llNewTimestamp;
>
> llLastTimestamp = llNewTimestamp;
> }
>
> //
> // Put the MIDI byte into the current event
> //
> if (aDMKEvt)
> {
> aDMKEvt->uData.abData[aDMKEvt->cbEvent] = (BYTE)
> dwMidiByte;
> aDMKEvt->cbEvent++;
> }
> }
>
> } while (ECHOSTATUS_OK == Status);
>
> KeReleaseSpinLockFromDpcLevel(m_pMiniport->m_pSpinLock);
>
> //
> // Dump the event queue back to the allocator
> //
> if (NULL != eventHead)
> {
> (void)m_sinkMXF->PutMessage(eventHead);
> }
>
> }
> else // render stream
> {
> DOUT(DBG_ERROR,("SourceEvtsToPort called on render stream"));
> ntStatus = STATUS_INVALID_DEVICE_REQUEST;
> }
> return ntStatus;
> }
>
> Hope that helps-
>
> Matt
>
> >From: wdmaudiodev-bounce@xxxxxxxxxxxxx
> >[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Philip Lukidis
> >Sent: Friday, November 28, 2003 7:22 AM
> >To: wdmaudiodev@xxxxxxxxxxxxx
> >Subject: [wdmaudiodev] Re: question on DMUS UART
> >
> >
> >OK...I patched portcls's call to KeInitializeDpc with my driver's
> >routine, which called KeInitializeDpc with the passed parameters, and
> >then called KeSetTargetProcessorDpc, making sure to pass a mask of 0.
> >So far it works fine (previously it would crash right away or in less
> >than 1 minute or so).
> >
> >This would seem to point to some synchronization problem on the part of
> >the DMUS port. So again I ask did anyone get DMUSUART to work on
> >multiple CPUs? Thanks.
> >
> >Philip Lukidis
> >
> >PS: I'll run it over the weekend here with driver verifier verifying
> >portcls.sys, with all options except low resources and DMA checking.
> >
> >
> >
>
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