Re: [edk2-devel] [PATCH v1 10/19] DynamicTablesPkg: Serial debug port initialisation

["Leif Lindholm" <leif.lindholm@linaro.org>]

On Thu, Nov 21, 2019 at 16:20:31 +0100, Philippe Mathieu-Daudé wrote:
> On 8/23/19 12:55 PM, Sami Mujawar wrote:
> > The ARM DCC serial port subtype is an option that is
> > supported by the DBG2 generator. However, the serial
> > port initialisation should only be done for PL011/SBSA
> > compatible UARTs.
> > 
> > Add check to conditionally initialise the serial port.
> > 
> > Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
> > ---
> >   DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c | 27 ++++++++++++--------
> >   1 file changed, 17 insertions(+), 10 deletions(-)
> > 
> > diff --git a/DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c b/DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c
> > index 346ab5b22f5402bf87c385558f68f080d1b454ed..51c843d25f75388104694855ce133b3d61860196 100644
> > --- a/DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c
> > +++ b/DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c
> > @@ -175,7 +175,7 @@ GET_OBJECT_LIST (
> >     CM_ARM_SERIAL_PORT_INFO
> >     );
> > -/** Initialize the PL011 UART with the parameters obtained from
> > +/** Initialize the PL011/SBSA UART with the parameters obtained from
> >       the Configuration Manager.
> 
> Isn't the SBSA UART a PL011?

No. It's a compatible subset.
So a PL011 can be used as an SBSA UART.

/
    Leif

> >     @param [in]  SerialPortInfo Pointer to the Serial Port Information.
> > @@ -353,15 +353,22 @@ BuildDbg2Table (
> >     AcpiDbg2.Dbg2DeviceInfo[DBG_PORT_INDEX_PORT1].Dbg2Device.PortSubtype =
> >       SerialPortInfo->PortSubtype;
> > -  // Initialize the serial port
> > -  Status = SetupDebugUart (SerialPortInfo);
> > -  if (EFI_ERROR (Status)) {
> > -    DEBUG ((
> > -      DEBUG_ERROR,
> > -      "ERROR: DBG2: Failed to configure debug serial port. Status = %r\n",
> > -      Status
> > -      ));
> > -    goto error_handler;
> > +  if ((SerialPortInfo->PortSubtype ==
> > +      EFI_ACPI_DBG2_PORT_SUBTYPE_SERIAL_ARM_PL011_UART)           ||
> > +      (SerialPortInfo->PortSubtype ==
> > +      EFI_ACPI_DBG2_PORT_SUBTYPE_SERIAL_ARM_SBSA_GENERIC_UART_2X) ||
> > +      (SerialPortInfo->PortSubtype ==
> > +      EFI_ACPI_DBG2_PORT_SUBTYPE_SERIAL_ARM_SBSA_GENERIC_UART)) {
> > +    // Initialize the serial port
> > +    Status = SetupDebugUart (SerialPortInfo);
> > +    if (EFI_ERROR (Status)) {
> > +      DEBUG ((
> > +        DEBUG_ERROR,
> > +        "ERROR: DBG2: Failed to configure debug serial port. Status = %r\n",
> > +        Status
> > +        ));
> > +      goto error_handler;
> > +    }
> >     }
> >     *Table = (EFI_ACPI_DESCRIPTION_HEADER*)&AcpiDbg2;
> > 
>