Re: [PATCH 02/24] Documentation: DT bindings: add more chip compatible strings for Tegra PCIe

Paul Walmsley
2015-01-29T17:29:39Z

On Thu, 29 Jan 2015, Paul Walmsley wrote:

> Hi Rob
>
> On Thu, 29 Jan 2015, Rob Herring wrote:
>
> > On Thu, Jan 29, 2015 at 9:45 AM, Paul Walmsley <paul@pwsan.com> wrote:
> > > On Thu, 29 Jan 2015, Rob Herring wrote:
> > >
> > >> On Wed, Jan 28, 2015 at 5:49 PM, Paul Walmsley <paul@pwsan.com> wrote:
> > >> >
> > >> > Add compatible strings for the PCIe IP blocks present on several Tegra
> > >> > chips. The primary objective here is to avoid checkpatch warnings,
> > >> > per:
> > >> >
> >
> > [...]
> >
> > >> > + - "nvidia,tegra132-pcie" (not yet matched in the driver)
> > >> > + - "nvidia,tegra210-pcie" (not yet matched in the driver)
> > >>
> > >> Whether the driver matches or not is irrelevant to the binding and may
> > >> change over time. Does this mean the driver matches on something else
> > >> or Tegra132 is not yet supported in the driver?
> > >
> > > It means that the driver currently matches on one of the first three
> > > strings that don't carry that annotation.
> > >
> > >> If the former, what is important is what are the valid combinations of
> > >> compatible properties and that is not captured here. In other words,
> > >> what is the fallback compatible string for each chip?
> > >
> > > The intention was to try to be helpful: to document that anyone adding a
> > > "nvidia,tegra132-pcie" compatible string would also need to add one of the
> > > other strings as a fallback. Would you like that to be documented in a
> > > different way, or removed?
> >
> > Then you should say something like 'must contain "nvidia,tegra20-pcie"
> > and one of: ...'
> >
> > You can also use nvidia,<chip>-pcie if you want. checkpatch will check
> > for that pattern too. Then your documentation can be something like:
> >
> > Must contain '"nvidia,<chip>-pcie", "nvidia,tegra20-pcie"' where
> > <chip> is tegra30, tegra132, ...
> >
> > We don't enforce that the <chip> part is documented ATM and not likely
> > until we have a schema if ever.
>
> OK, thanks for the explanation.
>
> So would it be acceptable to you to skip the attempt to document which
> strings are actually supported by the current driver, and to simply use
> the <chip> wildcard?

(Just in case it wasn't clear, I mean for the purposes of the current
patch series, not necessarily in general)

- Paul