linux-kernel - Re: [PATCH V2 1/2] opp: Allow dev_pm_opp_get_opp_table() to return -EPROBE

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]

Message-ID: <20201020093745.GA10604@bogus>
Date:   Tue, 20 Oct 2020 10:37:45 +0100
From:   Sudeep Holla <sudeep.holla@....com>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     ulf.hansson@...aro.org, "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Kevin Hilman <khilman@...nel.org>, Pavel Machek <pavel@....cz>,
        Len Brown <len.brown@...el.com>,
        Sudeep Holla <sudeep.holla@....com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...nel.org>, Kukjin Kim <kgene@...nel.org>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>, nks@...wful.org,
        georgi.djakov@...aro.org, Stephan Gerhold <stephan@...hold.net>,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org
Subject: Re: [PATCH V2 1/2] opp: Allow dev_pm_opp_get_opp_table() to return
 -EPROBE_DEFER

On Tue, Oct 20, 2020 at 11:24:32AM +0530, Viresh Kumar wrote:
> On 20-10-20, 10:35, Viresh Kumar wrote:
> > On 19-10-20, 15:10, Sudeep Holla wrote:
> > > On Mon, Oct 19, 2020 at 04:05:35PM +0530, Viresh Kumar wrote:
> > > > On 19-10-20, 11:12, Sudeep Holla wrote:
> > > > > Yes it has clocks property but used by SCMI(for CPUFreq/DevFreq) and not
> > > > > by any clock provider driver. E.g. the issue you will see if "clocks"
> > > > > property is used instead of "qcom,freq-domain" on Qcom parts.
> > > > 
> > > > Okay, I understand. But what I still don't understand is why it fails
> > > > for you. You have a clocks property in DT for the CPU, the OPP core
> > > > tries to get it and will get deferred-probed, which will try probing
> > > > at a later point of time and it shall work then. Isn't it ?
> > > >
> > > 
> > > Nope unfortunately. We don't have clock provider, so clk_get will
> > > never succeed and always return -EPROBE_DEFER.
> > 
> > Now this is really bad, you have a fake clocks property, how is the
> > OPP core supposed to know it ? Damn.
> 
> What about instead of fixing the OPP core, which really is doing the
> right thing, we fix your driver (as you can't fix the DT) and add a
> dummy CPU clk to make it all work ?
>

I really would avoid that. I would rather change the binding as there is
no single official users of that binding in the upstream tree.

-- 
Regards,
Sudeep