Re: [PATCH 1/4] firmware: xilinx: Add afi ioctl support

[Xu Yilun]

On 2022-08-30 at 09:25:47 +0000, Manne, Nava kishore wrote:
> Hi Yilun,
> 
> 	Please find my response inline. 
> 
> > -----Original Message-----
> > From: Xu Yilun <yilun.xu@xxxxxxxxx>
> > Sent: Saturday, August 27, 2022 11:52 AM
> > To: Manne, Nava kishore <nava.kishore.manne@xxxxxxx>
> > Cc: git (AMD-Xilinx) <git@xxxxxxx>; robh+dt@xxxxxxxxxx;
> > krzysztof.kozlowski+dt@xxxxxxxxxx; michal.simek@xxxxxxxxxx;
> > mdf@xxxxxxxxxx; hao.wu@xxxxxxxxx; trix@xxxxxxxxxx;
> > p.zabel@xxxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx;
> > ronak.jain@xxxxxxxxxx; rajan.vaja@xxxxxxxxxx;
> > abhyuday.godhasara@xxxxxxxxxx; piyush.mehta@xxxxxxxxxx;
> > lakshmi.sai.krishna.potthuri@xxxxxxxxxx; harsha.harsha@xxxxxxxxxx;
> > linus.walleij@xxxxxxxxxx; nava.manne@xxxxxxxxxx;
> > devicetree@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; linux-fpga@xxxxxxxxxxxxxxx; yilun.xu@xxxxxxxxx
> > Subject: Re: [PATCH 1/4] firmware: xilinx: Add afi ioctl support
> > 
> > On 2022-08-24 at 09:25:39 +0530, Nava kishore Manne wrote:
> > > Adds afi ioctl to support dynamic PS-PL bus width settings.
> > 
> > Please also describe what is afi, PS, PL here, Patch #0 won't appear in
> > upstream tree finally.
> > 
> 
> Agree, Will update the description in v2.
> 
> > Thanks,
> > Yilun
> > 
> > >
> > > Signed-off-by: Nava kishore Manne <nava.kishore.manne@xxxxxxx>
> > > ---
> > >  drivers/firmware/xilinx/zynqmp.c     | 14 +++++++++++
> > >  include/linux/firmware/xlnx-zynqmp.h | 36
> > > ++++++++++++++++++++++++++++
> > >  2 files changed, 50 insertions(+)
> > >
> > > diff --git a/drivers/firmware/xilinx/zynqmp.c
> > > b/drivers/firmware/xilinx/zynqmp.c
> > > index d1f652802181..cbd84c96a66a 100644
> > > --- a/drivers/firmware/xilinx/zynqmp.c
> > > +++ b/drivers/firmware/xilinx/zynqmp.c
> > > @@ -843,6 +843,20 @@ int zynqmp_pm_read_pggs(u32 index, u32
> > *value)  }
> > > EXPORT_SYMBOL_GPL(zynqmp_pm_read_pggs);
> > >
> > > +/**
> > > + * zynqmp_pm_afi() - PM API for setting the PS-PL bus width
> > > + * @config_id:	Register index value
> > > + * @bus_width:	Afi interface bus width value.
> > > + *
> > > + * Return:	Returns status, either success or error+reason
> > 
> > I see other functions are also like this, but I still can't figure out what values
> > for success and what for error+reason.
> > 
> 
> Please find the relevant error info here:
> https://elixir.bootlin.com/linux/v6.0-rc3/source/drivers/firmware/xilinx/zynqmp.c#L81

The caller should at least know what value is success and what are
failures from the kernel doc, so they could write the code which call
your API.

Thanks,
Yilun

> 
> Regards,
> Navakishore.
>