Re: [PATCH edk2-platforms v3 16/24] Silicon/NXP: Add Chassis2 Package

["Leif Lindholm" <leif@nuviainc.com>]

On Thu, Apr 23, 2020 at 14:45:03 +0000, Pankaj Bansal (OSS) wrote:
> > > > > You mean put ChassisLibConstructor() call in SerialPortInitialize () ?
> > > >
> > > > Or before the call to SerialPortInitialize in ChassisInit.
> > >
> > > But SerialPortInitialize would be called from each module.
> > 
> > Why would multiple modules need to initialize the serial port?
> 
> That's how the DebugLib has been designed.
> DebugLib is used by all modules to print info on console.
> BaseDebugLibSerialPortConstructor calls SerialPortInitialize.
> So SerialPortInitialize is called by all the modules.

Sure, but the bit where ChassisLib returns the active clock
configuration does not need to happen for each initialization.
That value can be cached.

> Which is the reason when I forked the BaseSerialPortLib16550,
> I removed SerialPortInitalize functionality.
> https://edk2.groups.io/g/devel/message/54011
> 
> > 
> > > Each module that has SerialPort and ChassiLib linked to it would have a
> > > local copy of mDcfgOps, which needs to be initialized.
> > 
> > On the surface it makes more sense for the function that initializes
> > mmio accessors for chassis to be in the chassis initialization
> > function.
> > 
> > In the current tree I can only see one user of SerialPortLib and one
> > of ChassisLib - but you are suggesting there will be several per
> > platform? If so, A better splution may ne to consider wrapping
> > DcfgRead32/DcfgWrite32 in a protocol instead of depending on the
> > ChassisLib.
> 
> The protocol would not be available in SEC and PEI phase.

Fair.

/
    Leif