Re: [PATCH v3 20/24] firmware: xilinx: Add APIs to read/write GGS/PGGS registers

[Greg KH]

On Wed, Mar 18, 2020 at 12:41:46PM +0000, Rajan Vaja wrote:
> Hi Greg,
> 
> Thanks for applying patches and review.
> 
> Please see my comment inline.
> 
> > -----Original Message-----
> > From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Sent: 18 March 2020 05:22 PM
> > To: Jolly Shah <JOLLYS@xxxxxxxxxx>
> > Cc: ard.biesheuvel@xxxxxxxxxx; mingo@xxxxxxxxxx; matt@xxxxxxxxxxxxxxxxxxx;
> > sudeep.holla@xxxxxxx; hkallweit1@xxxxxxxxx; keescook@xxxxxxxxxxxx;
> > dmitry.torokhov@xxxxxxxxx; Michal Simek <michals@xxxxxxxxxx>; Rajan Vaja
> > <RAJANV@xxxxxxxxxx>; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; Rajan Vaja <RAJANV@xxxxxxxxxx>
> > Subject: Re: [PATCH v3 20/24] firmware: xilinx: Add APIs to read/write GGS/PGGS
> > registers
> > 
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> > 
> > 
> > On Fri, Mar 06, 2020 at 03:47:28PM -0800, Jolly Shah wrote:
> > > --- a/include/linux/firmware/xlnx-zynqmp.h
> > > +++ b/include/linux/firmware/xlnx-zynqmp.h
> > > @@ -105,6 +105,10 @@ enum pm_ioctl_id {
> > >       IOCTL_GET_PLL_FRAC_MODE,
> > >       IOCTL_SET_PLL_FRAC_DATA,
> > >       IOCTL_GET_PLL_FRAC_DATA,
> > > +     IOCTL_WRITE_GGS,
> > > +     IOCTL_READ_GGS,
> > > +     IOCTL_WRITE_PGGS,
> > > +     IOCTL_READ_PGGS,
> > 
> > You do not have explicit numbers here?  Bold :)
> [Rajan] Here new IOCTL IDs are continuous so didn't mention explicit number.

Yes, but is that guaranteed by the compiler?  I keep getting conflicting
advice with that.

> Are asking for adding numbers like below:
> enum pm_ioctl_id {
>       ...
>       IOCTL_GET_PLL_FRAC_DATA = 11,
>       IOCTL_WRITE_GGS = 12,
>       ....
> }

Yes please, especially as your firmware is expecting the explicit values
here, right?  That way you _know_ everything is correct.

thanks,

greg k-h