Re: [PATCH] Tftp assert fix for openfile failure case

[Udit Kumar <udit.kumar@nxp.com>]

> -----Original Message-----
> From: Leif Lindholm [mailto:leif.lindholm@linaro.org]
> Sent: Wednesday, November 08, 2017 8:52 PM
> To: Udit Kumar <udit.kumar@nxp.com>
> Cc: Vabhav Sharma <vabhav.sharma@nxp.com>; edk2-devel@lists.01.org;
> ruiyu.ni@intel.com; jaben.carsey@intel.com; ard.biesheuvel@linaro.org;
> siyuan.fu@intel.com; ting.ye@intel.com
> Subject: Re: [PATCH] Tftp assert fix for openfile failure case
> 
> On Wed, Nov 08, 2017 at 05:15:49AM +0000, Udit Kumar wrote:
> > > > diff --git a/ShellPkg/Library/UefiShellTftpCommandLib/Tftp.c
> > > > b/ShellPkg/Library/UefiShellTftpCommandLib/Tftp.c
> > > > index fbde3bf..6425fc5 100755
> > > > --- a/ShellPkg/Library/UefiShellTftpCommandLib/Tftp.c
> > > > +++ b/ShellPkg/Library/UefiShellTftpCommandLib/Tftp.c
> > > > @@ -509,6 +509,7 @@ ShellCommandRunTftp (
> > > >        );
> > > >        goto NextHandle;
> > >
> > > Wow, a goto in a foor loop in a 320-line function.
> > > What could possibly go wrong?
> >
> > Instead of being on some volume, if you are on Shell.
> > Then file open will fail.
> 
> Sure. The above was a snarky comment on the state of the existing code.
> 
> > > >      }
> > > > +    DataSize = FileSize;
> > > >
> > > >      Status = DownloadFile (Mtftp4, RemoteFilePath,
> > > > AsciiRemoteFilePath,
> > > FileSize, BlockSize, &Data);
> > > >      if (EFI_ERROR (Status)) {
> > > > @@ -539,7 +540,6 @@ ShellCommandRunTftp (
> > > >        goto NextHandle;
> > > >      }
> > > >
> > > > -    DataSize = FileSize;
> > > >      Status = ShellWriteFile (FileHandle, &FileSize, Data);
> > > >      if (!EFI_ERROR (Status)) {
> > > >        ShellStatus = SHELL_SUCCESS;
> > > > --
> > > > 1.9.1
> > >
> > > So, a wider question:
> > > This shell command was introduced in the heyday of "let's
> > > reimplement U-Boot in the EDK2 tree". Mainly, from my impression, it
> > > seems to be used in order that people don't need to learn how boot
> > > managers and device paths work.
> >
> > When you say about complete boot, then this may not be useful.
> >
> > > Am I being too harsh?
> > > Are there practical uses for this?
> >
> > For doing some sort of unit testing of given interface. I found this
> > useful. During development, this is useful to transfer generic file to
> > development board.
> 
> OK, I can see how it could be useful.
> My opposition is based on three things:
> 1) people _are_ trying to use it for boot

I agree with this, please see my previous comments, 
' When you say about complete boot, then this may not be useful.'

> 2) not a command described by UEFI Shell spec, but I keep seeing
>    platforms including it even in RELEASE builds (most likely because 1)
> 3) code quality/maintainability

> > > If the code is to be kept, I think (from a quick glance) that I
> > > would also like to see
> > >   *Data = NULL
> > > in the error path of DownloadFile().
> 
> OK, so we don't need to drop it right now, but what's your take on this
> comment?

I am fine, if you prefer to remove this then we will develop some test application
for unit tests.
In case, we need to maintain this piece of code then above needs to fix as well. 

 
> /
>     Leif