Re: [[PATCH v2] 5/7] EmbeddedPkg: Fix DwEmmc driver bugs

["Loh, Tien Hock" <tien.hock.loh@intel.com>]

> -----Original Message-----
> From: Leif Lindholm <leif.lindholm@linaro.org>
> Sent: Friday, May 3, 2019 8:11 PM
> To: Loh, Tien Hock <tien.hock.loh@intel.com>
> Cc: devel@edk2.groups.io; thloh85@gmail.com; Ard Biesheuvel
> <ard.biesheuvel@linaro.org>
> Subject: Re: [[PATCH v2] 5/7] EmbeddedPkg: Fix DwEmmc driver bugs
> 
> On Fri, May 03, 2019 at 11:27:01AM +0800, tien.hock.loh@intel.com wrote:
> > From: "Tien Hock, Loh" <tien.hock.loh@intel.com>
> >
> > Send command when MMC ask for response in
> DwEmmcReceiveResponse, and
> > command is a pending command (eg. DMA needs to be set up first)
> >
> > Signed-off-by: "Tien Hock, Loh" <tien.hock.loh@intel.com>
> > Cc: Leif Lindholm <leif.lindholm@linaro.org>
> > Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> > ---
> >  EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c | 10 +++++++++-
> >  1 file changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> > b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> > index 32572a9..a69d9ab 100644
> > --- a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> > +++ b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
> > @@ -398,8 +398,11 @@ DwEmmcSendCommand (
> >      mDwEmmcCommand = Cmd;
> >      mDwEmmcArgument = Argument;
> >    } else {
> > +    mDwEmmcCommand = Cmd;
> > +    mDwEmmcArgument = Argument;
> >      Status = SendCommand (Cmd, Argument);
> >    }
> > +
> 
> I agree a space looks better here, but please don't add unrelated whitespace
> as part of a functional change.
OK noted. 
> 
> >    return Status;
> >  }
> >
> > @@ -410,6 +413,11 @@ DwEmmcReceiveResponse (
> >    IN UINT32*                    Buffer
> >    )
> >  {
> > +  EFI_STATUS Status = EFI_SUCCESS;
> > +
> > +  if(IsPendingReadCommand (mDwEmmcCommand) ||
> > + IsPendingWriteCommand(mDwEmmcCommand))
> 
>   {
> 
> > +    Status = SendCommand (mDwEmmcCommand, mDwEmmcArgument);
> 
>   }
> 
> > +
> >    if (Buffer == NULL) {
> >      return EFI_INVALID_PARAMETER;
> >    }
> 
> Should this test not come first in the function?
> If the code is relying on the side effect of the SendCommand () being
> performed even if Buffer is invalid, that needs a very detailed comment.

Yes I'll move it to after the buffer null check. 

> 
> /
>     Leif
> 
> 
> > @@ -427,7 +435,7 @@ DwEmmcReceiveResponse (
> >      Buffer[2] = MmioRead32 (DWEMMC_RESP2);
> >      Buffer[3] = MmioRead32 (DWEMMC_RESP3);
> >    }
> > -  return EFI_SUCCESS;
> > +  return Status;
> >  }
> >
> >  VOID
> > --
> > 2.2.2
> >