Re: [PATCH v2 4/6] fpga: dfl: add generic support for MSIX interrupts

[matthew . gerlach]

On Fri, 23 Sep 2022, Andy Shevchenko wrote:

> On Fri, Sep 23, 2022 at 05:17:43AM -0700, matthew.gerlach@xxxxxxxxxxxxxxx wrote:
> > From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
> >
> > Define and use a DFHv1 parameter to add generic support for MSIX
> > interrupts for DFL devices.
>
> ...
>
> > +	if (fid != FEATURE_ID_AFU && fid != PORT_FEATURE_ID_ERROR &&
> > +	    fid != PORT_FEATURE_ID_UINT && fid != FME_FEATURE_ID_GLOBAL_ERR) {
>
> > +
>
> Unneeded blank line.

I will remove the blank line.

> > +		v = FIELD_GET(DFH_VERSION, readq(base));
> > +		switch (v) {
>
> This v...
>
> > +		case 0:
> > +			break;
> > +
> > +		case 1:
> > +			v =  readq(base + DFHv1_CSR_SIZE_GRP);
>
> Extra space.
>
> ...and this v are semantically different. It's quite hard to deduce their
> semantics.

I was trying to be consistent with the existing code where the read was 
stored in a temporary variable, v, and the FIELD_GET would be used for the 
specific field.  Will it be sufficiently clear if the v used above is 
changed to dfl_ver, and this use of v followed by FIELD_GET remains as is?

> > +			if (FIELD_GET(DFHv1_CSR_SIZE_GRP_HAS_PARAMS, v)) {
> > +				off = dfl_find_param(base + DFHv1_PARAM_HDR, ofst,
> > +						     DFHv1_PARAM_ID_MSIX);
>
> I guess I have suggested to use temporary variable(s) here.
>
> 			void __iomem *dfhv1 = base + DFHv1...;
> 			void __iomem *nth;
>
> > +				if (off >= 0) {
>
> 					nth = dfhv1 + off;
>
> > +					ibase = readl(base + DFHv1_PARAM_HDR +
> > +						      off + DFHv1_PARAM_MSIX_STARTV);
> > +					inr = readl(base + DFHv1_PARAM_HDR +
> > +						    off + DFHv1_PARAM_MSIX_NUMV);
>
> 					ibase = readl(nth + DFHv1_PARAM_MSIX_STARTV);
> 					inr = readl(nth + DFHv1_PARAM_MSIX_NUMV);
>
> > +					dev_dbg(binfo->dev, "start %d num %d fid 0x%x\n",
> > +						ibase, inr, fid);
> > +				}
> > +			}
> > +			break;
> > +
> > +		default:
> > +			dev_warn(binfo->dev, "unexpected DFH version %lld\n", v);
> > +			break;
> > +		}
> > +	}
>
> --
> With Best Regards,
> Andy Shevchenko