Although this also updates Ard's code, mainly, I think I can comment on it:
On 11/17/15 10:35, Star Zeng wrote:
> Cc: Michael D Kinney <michael.d.kin...@intel.com>
> Cc: Liming Gao <liming....@intel.com>
> Cc: Jordan Justen <jordan.l.jus...@intel.com>
> Cc: Laszlo Ersek <ler...@redhat.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Star Zeng <star.z...@intel.com>
> ---
> .../XenConsoleSerialPortLib.c | 88
> ++++++++++++++++++++++
> 1 file changed, 88 insertions(+)
>
> diff --git
> a/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.c
> b/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.c
> index 4ccb38d..4e80a8f 100644
> --- a/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.c
> +++ b/OvmfPkg/Library/XenConsoleSerialPortLib/XenConsoleSerialPortLib.c
> @@ -2,6 +2,7 @@
> Xen console SerialPortLib instance
>
> Copyright (c) 2015, Linaro Ltd. All rights reserved.<BR>
> + Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
>
> This program and the accompanying materials
> are licensed and made available under the terms and conditions of the BSD
> License
> @@ -205,3 +206,90 @@ SerialPortPoll (
> return mXenConsoleInterface &&
> mXenConsoleInterface->in_cons != mXenConsoleInterface->in_prod;
> }
> +
> +/**
> + Sets the control bits on a serial device.
> +
> + @param Control Sets the bits of Control that are settable.
> +
> + @retval RETURN_SUCCESS The new control bits were set on the serial
> device.
> + @retval RETURN_UNSUPPORTED The serial device does not support this
> operation.
> + @retval RETURN_DEVICE_ERROR The serial device is not functioning
> correctly.
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +SerialPortSetControl (
> + IN UINT32 Control
> + )
> +{
> + return RETURN_UNSUPPORTED;
> +}
> +
> +/**
> + Retrieve the status of the control bits on a serial device.
> +
> + @param Control A pointer to return the current control
> signals from the serial device.
> +
> + @retval RETURN_SUCCESS The control bits were read from the serial
> device.
> + @retval RETURN_UNSUPPORTED The serial device does not support this
> operation.
> + @retval RETURN_DEVICE_ERROR The serial device is not functioning
> correctly.
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +SerialPortGetControl (
> + OUT UINT32 *Control
> + )
> +{
> + if (!mXenConsoleInterface) {
> + return RETURN_UNSUPPORTED;
> + }
> +
> + if (!SerialPortPoll ()) {
> + *Control = EFI_SERIAL_INPUT_BUFFER_EMPTY;
> + }
> + return RETURN_SUCCESS;
> +}
The problem I see here is that *Control is not set if SerialPortPoll()
returns TRUE. In that case, *Control remains unchanged (which could
imply "garbage from the caller"), despite the function returning
RETURN_SUCCESS.
So I propose the following:
if (!mXenConsoleInterface) {
return RETURN_UNSUPPORTED;
}
*Control = EFI_SERIAL_CARRIER_DETECT; /* or else, just set zero */
if (!SerialPortPoll ()) {
*Control |= EFI_SERIAL_INPUT_BUFFER_EMPTY;
}
return RETURN_SUCCESS;
Looks good otherwise.
Thanks
Laszlo
> +
> +/**
> + Sets the baud rate, receive FIFO depth, transmit/receice time out, parity,
> + data buts, and stop bits on a serial device.
> +
> + @param BaudRate The requested baud rate. A BaudRate value of 0
> will use the
> + device's default interface speed.
> + @param ReveiveFifoDepth The requested depth of the FIFO on the receive
> side of the
> + serial interface. A ReceiveFifoDepth value of 0
> will use
> + the device's default FIFO depth.
> + @param Timeout The requested time out for a single character in
> microseconds.
> + This timeout applies to both the transmit and
> receive side of the
> + interface. A Timeout value of 0 will use the
> device's default time
> + out value.
> + @param Parity The type of parity to use on this serial device.
> A Parity value of
> + DefaultParity will use the device's default
> parity value.
> + @param DataBits The number of data bits to use on the serial
> device. A DataBits
> + vaule of 0 will use the device's default data
> bit setting.
> + @param StopBits The number of stop bits to use on this serial
> device. A StopBits
> + value of DefaultStopBits will use the device's
> default number of
> + stop bits.
> +
> + @retval RETURN_SUCCESS The new attributes were set on the
> serial device.
> + @retval RETURN_UNSUPPORTED The serial device does not support this
> operation.
> + @retval RETURN_INVALID_PARAMETER One or more of the attributes has an
> unsupported value.
> + @retval RETURN_DEVICE_ERROR The serial device is not functioning
> correctly.
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +SerialPortSetAttributes (
> + IN OUT UINT64 *BaudRate,
> + IN OUT UINT32 *ReceiveFifoDepth,
> + IN OUT UINT32 *Timeout,
> + IN OUT EFI_PARITY_TYPE *Parity,
> + IN OUT UINT8 *DataBits,
> + IN OUT EFI_STOP_BITS_TYPE *StopBits
> + )
> +{
> + return RETURN_UNSUPPORTED;
> +}
> +
>
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