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EFI_USBFN_POLICY_TYPE

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The EFI_USBFN_POLICY_TYPE enumeration contains values used to indicate the type of endpoint.

Syntax

typedef enum _EFI_USBFN_POLICY_TYPE{
  EfiUsbPolicyUndefined = 0, 
  EfiUsbPolicyMaxTransactionSize, 
  EfiUsbPolicyZeroLengthTerminationSupport, 
  EfiUsbPolicyZeroLengthTermination
} EFI_USBFN_POLICY_TYPE;

Constants

EfiUsbPolicyUndefined
Invalid policy value that must never be used across a driver boundary. If used, the callee function must never return a success status code.

EfiUsbPolicyMaxTransactionSize
This policy is read-only. When used with EFI_USBFN_IO_PROTOCOL.GetEndpointPolicy, the size of the maximum single transaction (delivery of service to an endpoint) supported by a controller is returned. It must be more than or equal to the maximum transfer size that can be retrieved by calling EFI_USBFN_IO_PROTOCOL.GetMaxTransferSize.

  GetEndpointPolicy SetEndpointPolicy
BufferSize 4 bytes, sizeof(UINT32) Not applicable
Return status EFI_STATUS EFI_UNSUPPORTED

EfiUsbPolicyZeroLengthTerminationSupport
This policy is read-only. When used with EFI_USBFN_IO_PROTOCOL.GetEndpointPolicy, TRUE is returned if the USB controller hardware is capable of automatically handling zero-length packets when the transfer size is a multiple of USB maximum packet size; FALSE is returned if such a scenario is not supported by the controller hardware.

  GetEndpointPolicy SetEndpointPolicy
BufferSize 1 byte, sizeof(BOOLEAN) Not applicable
Return status EFI_STATUS EFI_UNSUPPORTED

EfiUsbPolicyZeroLengthTermination
When used with EFI_USBFN_IO_PROTOCOL.GetEndpointPolicy, TRUE is returned if the USB controller hardware is configured to automatically handle zero-length packets when the transfer size is a multiple of USB maximum packet size; FALSE is returned if the controller hardware is not configured to support such a scenario.

EFI_USBFN_IO_PROTOCOL.SetEndpointPolicy can only accept this policy type if the USB controller hardware is capable of supporting automatic zero-length packet termination. When this value is set to TRUE, the controller must be configured to handle zero-length termination for the specified endpoint; a FALSE value would not configure the controller in such fashion.

Even if the controller hardware is capable of supporting automatic zero-length termination, it must not be the default configuration.

  GetEndpointPolicy SetEndpointPolicy
BufferSize 1 byte, sizeof(BOOLEAN) 1 byte, sizeof(BOOLEAN)
Return status EFI_STATUS EFI_STATUS

Requirements

Header: User generated