Hello! I'm trying to get data (like audio) stream from custom vendor usb device with bulk endpoint. When I use AsyncIO
in cycle some data was lost. And I saw that AsyncIOBundled can help me with this issue.
I've trying to use it:
- Create memory buffers
for (int i = 0; i < DEFAULT_BUF_NUMBER; i++) {
kern_return_t ret = IOBufferMemoryDescriptor::Create(
kIOMemoryDirectionInOut,
DEFAULT_BUF_LENGTH,
0,
&ivars->buffers[i]
);
}
- Create MemoryDescriptorRing and set MemoryDescriptor for each index
kern_return_t MyDriver::SetupRingBuffer(IOMemoryDescriptor** memoryDescriptors, uint16_t length)
{
kern_return_t ret = kIOReturnSuccess;
ret = ivars->inPipe->CreateMemoryDescriptorRing(length);
if (ret != kIOReturnSuccess) {
IOLog("CreateMemoryDescriptorRing failed %s", StringFromReturn(ret));
return ret;
}
for (int i = 0; i < length; i++) {
ret = ivars->inPipe->SetMemoryDescriptor(memoryDescriptors[i], i);
if (ret != kIOReturnSuccess) {
IOLog("SetMemoryDescriptor failed %s", StringFromReturn(ret));
break;
}
}
return ret;
}
-
Create completion
-
Run AsyncIOBundled for only 1 index
ret = ivars->inPipe->AsyncIOBundled(
i,
1,
&transferAccepted,
(const unsigned int *)&ivars->dataBufferLengthArray,
DEFAULT_BUF_NUMBER,
ivars->readBundledCompletion,
0
);
- In completion i'm always get the error
0xe0005000 (UNDEFINED)
But if I use AsyncIO
with same buffer - it's success.
What am I doing wrong? There are no differences btw AsyncIOBundled and AsyncIO requests in wireshark