IOCTL_HID_SET_POLL_FREQUENCY_MSEC IOCTL

The IOCTL_HID_SET_POLL_FREQUENCY_MSEC request sets the polling frequency, in milliseconds, for a top-level collection.

User-mode applications or kernel-mode drivers that perform irregular, opportunistic reads on a polled device must furnish a polling interval of zero. In such cases, IOCTL_HID_SET_POLL_FREQUENCY_MSEC does not actually change the polling frequency of the device; but if the report data is not stale when it is read, the read is completed immediately with the latest report data for the indicated collection. If the report data is stale, it is refreshed immediately, without waiting for the expiration of the polling interval, and the read is completed with the new data.

If the value for the polling interval that is provided in the IRP is not zero, it must be >= MIN_POLL_INTERVAL_MSEC and <= MAX_POLL_INTERVAL_MSEC.

Polling may be limited if there are multiple top-level collections.

For general information about HIDClass devices, see HID Collections.

Major Code

IRP_MJ_DEVICE_CONTROL

Input Buffer

Parameters.DeviceIoControl.InputBufferLength in the I/O stack location of the IRP indicates the size, in bytes, of the input buffer, which must be >= sizeof(ULONG).

Irp->AssociatedIrp.SystemBuffer contains the new polling interval.

Input Buffer Length

A value greater than or equal to sizeof(ULONG).

Output Buffer

None.

Output Buffer Length

None.

Status Block

The HID class driver sets the Status member of Irp->IoStatus to STATUS_SUCCESS if the transfer completed without error. Otherwise, it is set to an appropriate NTSTATUS error code.

Requirements

   
Header hidclass.h (include Hidclass.h)

See Also

IOCTL_HID_GET_POLL_FREQUENCY_MSEC