[wdmaudiodev] Problem on setting wavecyclc
- From: "PB" <peterbla@xxxxxxxxxxx>
- To: <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Mon, 20 Jun 2005 00:18:49 +0800
I am writing an window audio driver by Microsoft
Window Driver Development Kit(DDK) for window XP.
I have followed the archecture of the driver sample
code provided under the folder SB16 which are using
WaveCyclic Interface and Slave Channel method to build
the sound card audio driver.
However, since our chip on the sound card have not
provide us the default channel, we use the Master Channel
method to create DMA channel and using allocate buffer API
similar as Slave method provided in the sample code.
------------------------------------------------------------
e.g.
ntStatus =
Port->NewMasterDmaChannel
(
&MyDmaChannel, // OutDmaChannel
NULL, // OuterUnknown (opt)
NULL, // ResourceList (opt)
MAXLEN_DMA_BUFFER, //Maximum Length
TRUE, // Dma32BitAddresses
FALSE, // Dma64BitAddresses
Width32Bits, // DmaWidth
Compatible
); // DmaPort
if (NT_SUCCESS(ntStatus))
{
ULONG lDMABufferLength = MAXLEN_DMA_BUFFER;
do {
ntStatus = MyDmaChannel->AllocateBuffer(lDMABufferLength,NULL);
lDMABufferLength >>= 1;
_DbgPrintF(DEBUGLVL_TERSE, ("lDMABufferLength = 0x%x",
lDMABufferLength));
} while (!NT_SUCCESS(ntStatus) && (lDMABufferLength > (PAGE_SIZE /
2)));
}
if (NT_SUCCESS(ntStatus))
{
....
AdapterCommon->WriteMCControlRegister((ULONG)PLAYBACK_DMA_CURRENT_BASE_ADDR,
(ULONG)MyDmaChannel->PhysicalAddress().QuadPart);
....
------------------------------------------------------------
However no matter how we tried, we cannot get the audio sound out.
We have seen in the debugger that all the register of our chip is now
controllable and the
address of the allocate addressed is sured can written to our audio chip.
We have seen the sequence in the window such as:
--------------------
[ValidateFormat]
[SetNotificationFreq]
[ServiceWaveISR]
[SetState]
--------------------
can be runned under the testing on debugger.
I have seen from the MSDN help menu that for master channel, user need to
use the API "copyto", "copyfrom" to copy data from and to the audio buffer.
It seems that it is not necessary in the slave channel method. Is it really
necessary in the master channel method?
And how can I know the address of where the data come from when Window Media
wave file? I have no method to fill in the parameter of the "copyto",
"copyfrom" API to use them.
Or anyone can post the reference code for masterchannel of Driver?
Thans you very much
Best Regards,
Peter
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