Re: [PATCH v1 1/1] fpga: dfl: pci: Use pci_find_vsec_capability() when looking for DFL

[Tom Rix]

On 11/9/21 10:05 AM, Andy Shevchenko wrote:
> On Tue, Nov 09, 2021 at 07:55:43AM -0800, Tom Rix wrote:
> > On 11/9/21 7:41 AM, Andy Shevchenko wrote:
> > > Currently the find_dfls_by_vsec() opens code pci_find_vsec_capability().
> > > Refactor the former to use the latter. No functional change intended.
> Thanks for review, my answers below.
>
> ...
>
> > > +	u16 voff;
> > The later use of voff in pci_read_config_dword is of type 'int', it may be
> > better to keep voff as an int.
> I don't think so. The rule of thumb that the types should match the value they
> got in the first place. In this case it's u16. Compiler will implicitly cast it
> to whatever is needed as long as the type is good for integer promotion.
>
> ...
>
> > > +	voff = pci_find_vsec_capability(dev, PCI_VENDOR_ID_INTEL, PCI_VSEC_ID_INTEL_DFLS);
> > This may be a weakness in the origin code, but intel isn't the exclusive
> > user of DFL.
> This does not change the original code. If you think so, this can be extended
> later on.

I would rather see this fixed now or explained why this isn't a problem.

Tom

> > >    	if (!voff) {
> > >    		dev_dbg(&pcidev->dev, "%s no DFL VSEC found\n", __func__);
> > >    		return -ENODEV;