Re: [PATCH v2 7/9] ARM: STi: DT: STiH407: Add FDMA driver dt nodes.

From: Lee Jones
Date: Fri Sep 11 2015 - 15:33:56 EST


On Fri, 11 Sep 2015, Peter Griffin wrote:
> On Fri, 11 Sep 2015, Lee Jones wrote:
> > On Fri, 11 Sep 2015, Peter Griffin wrote:
> > > On Fri, 11 Sep 2015, Lee Jones wrote:
> > > > On Fri, 11 Sep 2015, Peter Griffin wrote:
> > > >
> > > > > These nodes are required to get the fdma driver working
> > > > > on STiH407 based silicon.
> > > > >
> > > > > Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
> > > > > ---
> > > > > arch/arm/boot/dts/stih407-family.dtsi | 51 +++++++++++++++++++++++++++++++++++
> > > > > 1 file changed, 51 insertions(+)
> > > > >
> > > > > diff --git a/arch/arm/boot/dts/stih407-family.dtsi b/arch/arm/boot/dts/stih407-family.dtsi
> > > > > index 838b812..da07474b 100644
> > > > > --- a/arch/arm/boot/dts/stih407-family.dtsi
> > > > > +++ b/arch/arm/boot/dts/stih407-family.dtsi
> > > > > @@ -565,5 +565,56 @@
> > > > > <&phy_port2 PHY_TYPE_USB3>;
> > > > > };
> > > > > };
> > > > > +
> > > > > + fdma0: fdma0-audio@8e20000 {
> > > >
> > > > I'm not familiar with the FDMA driver, so can't comment knowledgeably,
> > > > but the <dev> part of <dev>@<base_address> should only describe the
> > > > type of hardware. I believe in this case it should just be
> > > > dma@08e20000. Also notice the leading zero in the address, which I
> > > > believe mitigates possible confusion. Then you be more specific with
> > > > the label, so something like 'fdma-audio' seems appropriate here.
> > >
> > > Ok, can change to that format in v3.
> > >
> > > >
> > > > > + compatible = "st,stih407-fdma-mpe31";
> > > > > + reg = <0x8e20000 0x20000>;
> > > >
> > > > I personally find padding up to 32bits helpful in the addresses.
> > >
> > > None of the stih407-family nodes I can see have this padding, including
> > > the ones merged by you.
> >
> > Nither of these two facts mean it's correct.
>
> I thought it was a 'personal' thing. If it is mandated by the spec, then that
> is different.
>
> >
> > I'm happy to write a patch to correct them all.
>
> Are you sure your actually correcting anything? Where does it say you
> should have a leading zero?
>
> >
> > Bear in mind that this isn't a hard and fast rule. Both work and are
> > legal. I just think the padding is more consistent.
>
> Surely adding a patch with how the nodes are currently formatted, is more consistent
> than adding a patch with padding?

I did mean consistent with the majority of DTS files, rather than just
ours. There are examples of non-padded values and it's perfectly
legal, but the vast majority of examples do in fact pad their
addresses [see below]. The change is more of a nit than a blocker.

git grep '@0[0-9|a-f]\{7\}' -- arch/arm/boot/dts/
892

git grep '@[0-9|a-f]\{7\} ' -- arch/arm/boot/dts/ | grep -vi sti | \
grep -vi partition | grep -vi data
140

I'll probably still fix them up and resubmit some patches to bring us
into line with the vast majority.

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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