[...]
The above analysis is very clear, thanks. I am a little concern about if
the code changes below follow the comments in the code.
In Terminal.c:
//
// Set the timeout value of serial buffer for
// keystroke response performance issue
//
In TerminalConIn.c:
//
// if current timeout value for serial device is not identical with
// the value saved in TERMINAL_DEV structure, then recalculate the
// timeout value again and set serial attribute according to this
value.
//
And I also checked the
IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe/Serial.c although ARM
platforms do not use it, the SERIAL_PORT_DEFAULT_RECEIVE_FIFO_DEPTH
value is 1. if SetAttributes() is called with ReceiveFifoDepth = 0, then
SERIAL_PORT_DEFAULT_RECEIVE_FIFO_DEPTH is selected as the description of
the functions is "A ReceiveFifoDepth value of 0 will use the device's
default FIFO depth", so what's the device's default FIFO depth?
I have a thought that updates SerialDxe to call SerialSetAttributes(with
0, 0, 0, DefaultParity, 0 and DefaultStopBits) in SerialDxeInitialize()
and SerialReset() to get the real default values of the device, then the
driver can also eliminate the use of PcdUartDefault####.
Try to explain the thought by below patch (not tested yet).
3cc4f3e688471946048de7ea67e0a73631844fad
MdeModulePkg/Universal/SerialDxe/SerialDxe.inf | 7 ---
MdeModulePkg/Universal/SerialDxe/SerialIo.c | 69
+++++++++++++-------------
2 files changed, 35 insertions(+), 41 deletions(-)
diff --git a/MdeModulePkg/Universal/SerialDxe/SerialDxe.inf
b/MdeModulePkg/Universal/SerialDxe/SerialDxe.inf
index 164060b..9e35c03 100644
--- a/MdeModulePkg/Universal/SerialDxe/SerialDxe.inf
+++ b/MdeModulePkg/Universal/SerialDxe/SerialDxe.inf
@@ -33,19 +33,12 @@
UefiDriverEntryPoint
UefiBootServicesTableLib
DebugLib
- PcdLib
SerialPortLib
[Protocols]
gEfiSerialIoProtocolGuid ## PRODUCES
gEfiDevicePathProtocolGuid ## PRODUCES
-[Pcd]
- gEfiMdePkgTokenSpaceGuid.PcdUartDefaultBaudRate ## CONSUMES
- gEfiMdePkgTokenSpaceGuid.PcdUartDefaultDataBits ## CONSUMES
- gEfiMdePkgTokenSpaceGuid.PcdUartDefaultParity ## CONSUMES
- gEfiMdePkgTokenSpaceGuid.PcdUartDefaultStopBits ## CONSUMES
-
[Depex]
TRUE
diff --git a/MdeModulePkg/Universal/SerialDxe/SerialIo.c
b/MdeModulePkg/Universal/SerialDxe/SerialIo.c
index de928d1..3985598 100644
--- a/MdeModulePkg/Universal/SerialDxe/SerialIo.c
+++ b/MdeModulePkg/Universal/SerialDxe/SerialIo.c
@@ -18,7 +18,6 @@
#include <Library/UefiBootServicesTableLib.h>
#include <Library/SerialPortLib.h>
#include <Library/DebugLib.h>
-#include <Library/PcdLib.h>
#include <Protocol/SerialIo.h>
#include <Protocol/DevicePath.h>
@@ -180,15 +179,7 @@ SERIAL_DEVICE_PATH mSerialDevicePath = {
//
// Template used to initialize the Serial IO protocols.
//
-EFI_SERIAL_IO_MODE mSerialIoMode = {
- 0, // ControlMask
- 0, // Timeout
- 0, // BaudRate
- 1, // ReceiveFifoDepth
- 0, // DataBits
- 0, // Parity
- 0 // StopBits
-};
+EFI_SERIAL_IO_MODE mSerialIoMode;
EFI_SERIAL_IO_PROTOCOL mSerialIoTemplate = {
SERIAL_IO_INTERFACE_REVISION,
@@ -201,6 +192,34 @@ EFI_SERIAL_IO_PROTOCOL mSerialIoTemplate = {
&mSerialIoMode
};
+EFI_STATUS
+SerialDeviceInitialize (
+ IN EFI_SERIAL_IO_MODE *SerialIoMode
+ )
+{
+ EFI_STATUS Status;
+
+ Status = SerialPortInitialize ();
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ //
+ // Get the real default value of the device.
+ //
+ ZeroMem (&SerialIoMode, sizeof (SerialIoMode));
+ Status = SerialPortSetAttributes (
+ &SerialIoMode->BaudRate,
+ &SerialIoMode->ReceiveFifoDepth,
+ &SerialIoMode->Timeout,
+ (EFI_PARITY_TYPE *) &SerialIoMode->Parity,
+ &SerialIoMode->DataBits,
+ (EFI_STOP_BITS_TYPE *) &SerialIoMode->StopBits);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+}
+
/**
Reset the serial device.
@@ -219,28 +238,14 @@ SerialReset (
EFI_STATUS Status;
EFI_TPL Tpl;
- Status = SerialPortInitialize ();
+ Status = SerialDeviceInitialize (&This->Mode);
if (EFI_ERROR (Status)) {
return Status;
}
- //
- // Set the Serial I/O mode and update the device path
- //
-
Tpl = gBS->RaiseTPL (TPL_NOTIFY);
//
- // Set the Serial I/O mode
- //
- This->Mode->ReceiveFifoDepth = 1;
- This->Mode->Timeout = 0;
- This->Mode->BaudRate = PcdGet64 (PcdUartDefaultBaudRate);
- This->Mode->DataBits = (UINT32) PcdGet8
(PcdUartDefaultDataBits);
- This->Mode->Parity = (UINT32) PcdGet8 (PcdUartDefaultParity);
- This->Mode->StopBits = (UINT32) PcdGet8
(PcdUartDefaultStopBits);
-
- //
// Check if the device path has actually changed
//
if (mSerialDevicePath.Uart.BaudRate == This->Mode->BaudRate &&
@@ -496,19 +501,15 @@ SerialDxeInitialize (
{
EFI_STATUS Status;
- Status = SerialPortInitialize ();
+ Status = SerialDeviceInitialize (&mSerialIoMode);
if (EFI_ERROR (Status)) {
return Status;
}
- mSerialIoMode.BaudRate = PcdGet64 (PcdUartDefaultBaudRate);
- mSerialIoMode.DataBits = (UINT32) PcdGet8 (PcdUartDefaultDataBits);
- mSerialIoMode.Parity = (UINT32) PcdGet8 (PcdUartDefaultParity);
- mSerialIoMode.StopBits = (UINT32) PcdGet8 (PcdUartDefaultStopBits);
- mSerialDevicePath.Uart.BaudRate = PcdGet64 (PcdUartDefaultBaudRate);
- mSerialDevicePath.Uart.DataBits = PcdGet8 (PcdUartDefaultDataBits);
- mSerialDevicePath.Uart.Parity = PcdGet8 (PcdUartDefaultParity);
- mSerialDevicePath.Uart.StopBits = PcdGet8 (PcdUartDefaultStopBits);
+ mSerialDevicePath.Uart.BaudRate = mSerialIoMode.BaudRate;
+ mSerialDevicePath.Uart.DataBits = (UINT8) mSerialIoMode.DataBits;
+ mSerialDevicePath.Uart.Parity = (UINT8) mSerialIoMode.Parity;
+ mSerialDevicePath.Uart.StopBits = (UINT8) mSerialIoMode.StopBits;
//
// Make a new handle with Serial IO protocol and its device path on it.
What's your opinion?
Thanks,
Star
[...]
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