Re: [PATCH v2 1/2] arm64: dts: renesas: r8a77990: Add cpg reset for LVDS Interface

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Simon Horman <horms@verge.net.au>
Cc: Takeshi Kihara <takeshi.kihara.df@renesas.com>,
	Yoshihiro Kaneko <ykaneko0929@gmail.com>,
	Magnus Damm <magnus.damm@gmail.com>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2 1/2] arm64: dts: renesas: r8a77990: Add cpg reset for LVDS Interface
Date: Tue, 18 Jun 2019 13:19:02 +0200	[thread overview]
Message-ID: <CAMuHMdVFn+sTXhbsM_tUsqSPeAG4b=zbUne=FaQedZgCBo4_oQ@mail.gmail.com> (raw)
In-Reply-To: <20190618104455.72jyrvwf2vut76hy@verge.net.au>

Hi Simon,

On Tue, Jun 18, 2019 at 12:45 PM Simon Horman <horms@verge.net.au> wrote:
> On Mon, Jun 17, 2019 at 10:43:09AM +0200, Geert Uytterhoeven wrote:
> > On Mon, Jun 17, 2019 at 10:37 AM Simon Horman
> > <horms+renesas@verge.net.au> wrote:
> > > From: Takeshi Kihara <takeshi.kihara.df@renesas.com>
> > >
> > > It is necessary to reset the LVDS Interface according to display on/off.
> >
> > This is not the LVDS interface.
> > The LVDS interface has its own device node.
>
> Thanks, how about a changelog more like this?
>
> arm64: dts: renesas: r8a77990: Add cpg reset for DU
>
> Add CPG reset properties to DU node of E3 (r8a77990) SoC.

Thanks, much better.

> According to Laurent Pinchart, R-Car Gen3 reset is handled at the group
> level so specifying one reset entry per group is sufficient. For this
> reason <&cpg 724> is not listed as a reset for "du.1" as was the case in an
> earlier revision of this patch.

Do we need this last sentence?

Note that "dt-bindings: display: renesas: du: Document optional reset
properties"
hasn't been accepted in -next yet.

> Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
> Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
>
> > > Therefore, this patch adds CPG reset properties in DU device node
> > > for the R8A77990 SoC.
> > >
> > > According to Laurent Pinchart, R-Car Gen3 reset is handled at the group
> > > level so specifying one reset entry per group is sufficient. For this
> > > reason <&cpg 724> is not listed as a reset for "du.1" as was the case in an
> > > earlier revision of this patch.
> > >
> > > Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
> > > Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
> > > Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
> > > ---
> > > v2 [Simon Horman]
> > > - only add one reset entry per group

> > > --- a/arch/arm64/boot/dts/renesas/r8a77990.dtsi
> > > +++ b/arch/arm64/boot/dts/renesas/r8a77990.dtsi
> > > @@ -1766,6 +1766,8 @@
> > >                         clocks = <&cpg CPG_MOD 724>,
> > >                                  <&cpg CPG_MOD 723>;
> > >                         clock-names = "du.0", "du.1";
> > > +                       resets = <&cpg 724>;
> > > +                       reset-names = "du.0";
> > >                         vsps = <&vspd0 0 &vspd1 0>;
> > >                         status = "disabled";

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

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