linux-kernel - Re: [PATCH 2/5] clk: qcom: apcs-msm8916: get parent clock names from DT

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 10 Sep 2019 02:14:36 -0700
From:   Stephen Boyd <sboyd@...nel.org>
To:     "Jorge Ramirez-Ortiz, Linaro" <jorge.ramirez-ortiz@...aro.org>
Cc:     "Jorge Ramirez-Ortiz, Linaro" <jorge.ramirez-ortiz@...aro.org>,
        agross@...nel.org, mturquette@...libre.com,
        bjorn.andersson@...aro.org, niklas.cassel@...aro.org,
        linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/5] clk: qcom: apcs-msm8916: get parent clock names from DT

Quoting Jorge Ramirez-Ortiz, Linaro (2019-09-09 09:54:08)
> On 09/09/19 09:17:03, Stephen Boyd wrote:
> > But now the binding is different for the same compatible. I'd prefer we
> > keep using devm_clk_get() and use a device pointer here and reorder the
> > map and parent arrays instead. The clocks property shouldn't change in a
> > way that isn't "additive" so that we maintain backwards compatibility.
> > 
> 
> but the backwards compatibility is fully maintained - that is the main reason
> behind the change. the new stuff is that  instead of hardcoding the
> names in the source - like it is being done on the msm8916- we provide
> the clocks in the dts node (a cleaner approach with the obvious
> benefit of allowing new users to be added without having to modify the
> sources).
> 

This is not a backwards compatible change.

> > > --- a/arch/arm64/boot/dts/qcom/msm8916.dtsi
> > > +++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi
> > > @@ -429,7 +429,8 @@
> > >      compatible = "qcom,msm8916-apcs-kpss-global", "syscon";
> > >      reg = <0xb011000 0x1000>;
> > >      #mbox-cells = <1>;
> > > -                   clocks = <&a53pll>;
> > > +                 clocks = <&gcc GPLL0_VOTE>, <&a53pll>;
> > > +                 clock-names = "aux", "pll";
> > >                       #clock-cells = <0>;
> > >                };
> > >                                                                                                                 

Because the "clocks" property changed from

	<&a53pll>

to

	<&gcc GPLL0_VOTE>, <&a53pll>

and that moves pll to cell 1 instead of cell 0.