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/*++
Copyright (c) Microsoft Corporation
Module Name:
purge.c
Abstract:
This module contains the code that is very specific to purge
operations in the serial driver
Environment:
Kernel mode
--*/
#include "precomp.h"
#if defined(EVENT_TRACING)
#include "purge.tmh"
#endif
VOID
SerialStartPurge(
IN PSERIAL_DEVICE_EXTENSION Extension
)
/*++
Routine Description:
Depending on the mask in the current request, purge the interrupt
buffer, the read queue, or the write queue, or all of the above.
Arguments:
Extension - Pointer to the device extension.
Return Value:
Will return STATUS_SUCCESS always. This is reasonable
since the DPC completion code that calls this routine doesn't
care and the purge request always goes through to completion
once it's started.
--*/
{
WDFREQUEST NewRequest;
PREQUEST_CONTEXT reqContext;
do {
ULONG Mask;
reqContext = SerialGetRequestContext(Extension->CurrentPurgeRequest);
Mask = *((ULONG *) (reqContext->SystemBuffer));
if (Mask & SERIAL_PURGE_TXABORT) {
SerialFlushRequests(
Extension->WriteQueue,
&Extension->CurrentWriteRequest
);
SerialFlushRequests(
Extension->WriteQueue,
&Extension->CurrentXoffRequest
);
}
if (Mask & SERIAL_PURGE_RXABORT) {
SerialFlushRequests(
Extension->ReadQueue,
&Extension->CurrentReadRequest
);
}
if (Mask & SERIAL_PURGE_RXCLEAR) {
//
// Clean out the interrupt buffer.
//
// Note that we do this under protection of the
// the drivers control lock so that we don't hose
// the pointers if there is currently a read that
// is reading out of the buffer.
//
WdfInterruptSynchronize(
Extension->WdfInterrupt,
SerialPurgeInterruptBuff,
Extension
);
}
reqContext->Status = STATUS_SUCCESS;
reqContext->Information = 0;
SerialGetNextRequest(
&Extension->CurrentPurgeRequest,
Extension->PurgeQueue,
&NewRequest,
TRUE,
Extension
);
} while (NewRequest);
return;
}
BOOLEAN
SerialPurgeInterruptBuff(
IN WDFINTERRUPT Interrupt,
IN PVOID Context
)
/*++
Routine Description:
This routine simply resets the interrupt (typeahead) buffer.
NOTE: This routine is being called from WdfInterruptSynchronize.
Arguments:
Context - Really a pointer to the device extension.
Return Value:
Always false.
--*/
{
PSERIAL_DEVICE_EXTENSION Extension = Context;
UNREFERENCED_PARAMETER(Interrupt);
//
// The typeahead buffer is by definition empty if there
// currently is a read owned by the isr.
//
if (Extension->ReadBufferBase == Extension->InterruptReadBuffer) {
Extension->CurrentCharSlot = Extension->InterruptReadBuffer;
Extension->FirstReadableChar = Extension->InterruptReadBuffer;
Extension->LastCharSlot = Extension->InterruptReadBuffer +
(Extension->BufferSize - 1);
Extension->CharsInInterruptBuffer = 0;
SerialHandleReducedIntBuffer(Extension);
}
return FALSE;
}
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