IOCTL_SERIAL_APPLY_DEFAULT_CONFIGURATION IOCTL (ntddser.h)

The IOCTL_SERIAL_APPLY_DEFAULT_CONFIGURATION control code configures the serial port to use the default hardware settings for the serial controller device. These settings are obtained from the ACPI resource descriptor for the serial controller device. For more information, see the ACPI 5.0 specification.

Major code

IRP_MJ_DEVICE_CONTROL

Input buffer

None.

Input buffer length

None.

Output buffer

None.

Output buffer length

None.

Status block

The Information member is set to zero.

The Status member is set to one of the generic status values for serial device control requests. A status of STATUS_NOT_IMPLEMENTED indicates that the serial port does not support a default configuration. In this case, the client must use the other IOCTL_SERIAL_XXX I/O control requests to explicitly configure the serial port.

Remarks

The client (application or peripheral device driver) sends this IOCTL to configure the serial port to use a set of default connection settings. These settings include connection-specific hardware parameters such as the baud rate, time-out values, and flow-control flags.

This IOCTL is supported by versions 1 and 2 of the serial framework extension (SerCx and SerCx2). Serial.sys, which manages the named serial ports (COM1, COM2, and so on) on a PC, does not support this IOCTL.

If a serial port does not support this IOCTL, the client must explicitly specify the connection settings for the port. That is, the client must send an IOCTL_SERIAL_SET_BAUD_RATE request to set the baud rate, send an IOCTL_SERIAL_SET_TIMEOUTS request to set the time-out intervals, and so on.

Immediately after a client opens a serial port, the client should assume that the port is configured in an unknown, uninitialized state rather than in some known, default state.

Requirements

Requirement	Value
Minimum supported client	Supported starting with Windows 8.
Header	ntddser.h (include Ntddser.h)

See also

IOCTL_SERIAL_SET_BAUD_RATE

IOCTL_SERIAL_SET_TIMEOUTS