IMiniportWaveCyclicStream::SetNotificationFreq method (portcls.h)

Article
02/22/2024

The SetNotificationFreq method controls the frequency at which notification interrupts are generated by setting the interval between successive interrupts.

Syntax

ULONG SetNotificationFreq(
  [in]  ULONG  Interval,
  [out] PULONG FrameSize
);

Parameters

[in] Interval

Specifies the interval between notification interrupts. This parameter value is expressed in milliseconds.

[out] FrameSize

Output pointer for the frame size. This parameter points to a caller-allocated variable into which the method writes the maximum number of bytes that can be transferred in Interval milliseconds. This byte count determines the size of the buffer that needs to be allocated for the input or output stream.

Return value

SetNotificationFreq returns the new notification interval expressed in milliseconds. In all current Windows releases, the port driver ignores this value.

Remarks

During each notification interrupt, the miniport driver's interrupt service routine calls the IPortWaveCyclic::Notify method with the stream's IServiceGroup object as the call parameter. This is the IServiceGroup object that the miniport driver previously output to the port driver during the IMiniportWaveCyclic::NewStream call.

In all current Windows releases, the WaveCyclic port driver specifies an Interval value of 10 milliseconds. This value might change in future releases.

Requirements

Requirement	Value
Target Platform	Universal
Header	portcls.h (include Portcls.h)
IRQL	PASSIVE_LEVEL