From: Viresh Kumar <viresh.kumar@linaro.org>
To: Sudeep Holla <sudeep.holla@arm.com>
Cc: ulf.hansson@linaro.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Kevin Hilman <khilman@kernel.org>, Pavel Machek <pavel@ucw.cz>,
Len Brown <len.brown@intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
Stephen Boyd <sboyd@kernel.org>, Kukjin Kim <kgene@kernel.org>,
Krzysztof Kozlowski <krzk@kernel.org>,
linux-pm@vger.kernel.org,
Vincent Guittot <vincent.guittot@linaro.org>,
nks@flawful.org, georgi.djakov@linaro.org,
Stephan Gerhold <stephan@gerhold.net>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org
Subject: Re: [PATCH V2 1/2] opp: Allow dev_pm_opp_get_opp_table() to return -EPROBE_DEFER
Date: Mon, 19 Oct 2020 14:54:11 +0530 [thread overview]
Message-ID: <20201019092411.b3znjxebay3puq2j@vireshk-i7> (raw)
In-Reply-To: <20201019091723.GA12087@bogus>
On 19-10-20, 10:17, Sudeep Holla wrote:
> On Mon, Oct 19, 2020 at 10:28:27AM +0530, Viresh Kumar wrote:
> > On 16-10-20, 12:12, Sudeep Holla wrote:
> > > On Fri, Oct 16, 2020 at 07:00:21AM +0100, Sudeep Holla wrote:
> > > > On Fri, Oct 16, 2020 at 09:54:34AM +0530, Viresh Kumar wrote:
> > > > > On 15-10-20, 19:05, Sudeep Holla wrote:
> > > > > > OK, this breaks with SCMI which doesn't provide clocks but manage OPPs
> > > > > > directly. Before this change clk_get(dev..) was allowed to fail and
> > > > > > --EPROBE_DEFER was not an error.
> > > > >
> > > > > I think the change in itself is fine. We should be returning from
> > > > > there if we get EPROBE_DEFER. The question is rather why are you
> > > > > getting EPROBE_DEFER here ?
> > > > >
> > > >
> > > > Ah OK, I didn't spend too much time, saw -EPROBE_DEFER, just reverted
> > > > this patch and it worked. I need to check it in detail yet.
> > > >
> > >
> > > You confused me earlier. As I said there will be no clock provider
> > > registered for SCMI CPU/Dev DVFS.
> > > opp_table->clk = clk_get(dev, NULL);
> > > will always return -EPROBE_DEFER as there is no clock provider for dev.
> > > But this change now propagates that error to caller of dev_pm_opp_add
> > > which means we can't add opp to a device if there are no clock providers.
> > > This breaks for DVFS which don't operate separately with clocks and
> > > regulators.
> >
> > The CPUs DT node shouldn't have a clock property in such a case and I
> > would expect an error instead of EPROBE_DEFER then. Isn't it ?
>
> Ideally yes, but for legacy reasons clocks property has been used for
> providing OPP/DVFS handle too. While we can change and add new property
> for that, it will still break old bindings.
I am not sure I understood it all. So does your platform have the
clock-names property or not for the CPUs ? And how will something
break here ?
--
viresh
next prev parent reply other threads:[~2020-10-19 9:24 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-24 9:09 [PATCH V2 1/2] opp: Allow dev_pm_opp_get_opp_table() to return -EPROBE_DEFER Viresh Kumar
2020-08-24 9:09 ` [PATCH V2 2/2] cpufreq: dt: Refactor initialization to handle probe deferral properly Viresh Kumar
[not found] ` <CGME20200901085708eucas1p231ccacd7b41685ece92ee21e3b726f28@eucas1p2.samsung.com>
2020-09-01 8:57 ` Marek Szyprowski
2020-09-01 9:45 ` Viresh Kumar
2020-09-01 10:05 ` Marek Szyprowski
2020-09-01 10:12 ` Viresh Kumar
2020-10-13 9:47 ` Geert Uytterhoeven
2020-10-13 9:56 ` Viresh Kumar
2020-10-14 16:40 ` Geert Uytterhoeven
2020-10-16 5:03 ` Viresh Kumar
2020-10-16 6:44 ` Geert Uytterhoeven
2020-10-16 8:07 ` Viresh Kumar
2020-10-27 16:29 ` Geert Uytterhoeven
2020-10-28 5:48 ` Viresh Kumar
2020-10-28 9:49 ` Geert Uytterhoeven
2020-10-28 9:52 ` Viresh Kumar
2020-08-24 9:17 ` [PATCH V2 1/2] opp: Allow dev_pm_opp_get_opp_table() to return -EPROBE_DEFER Krzysztof Kozlowski
2020-08-24 11:08 ` Ulf Hansson
2020-08-24 11:39 ` Stephan Gerhold
2020-10-15 18:05 ` Sudeep Holla
2020-10-16 4:24 ` Viresh Kumar
2020-10-16 6:00 ` Sudeep Holla
2020-10-16 11:12 ` Sudeep Holla
2020-10-16 15:28 ` Stephan Gerhold
2020-10-19 4:58 ` Viresh Kumar
2020-10-19 9:17 ` Sudeep Holla
2020-10-19 9:24 ` Viresh Kumar [this message]
2020-10-19 10:12 ` Sudeep Holla
2020-10-19 10:35 ` Viresh Kumar
2020-10-19 14:10 ` Sudeep Holla
2020-10-20 5:05 ` Viresh Kumar
2020-10-20 5:54 ` Viresh Kumar
2020-10-20 9:37 ` Sudeep Holla
2020-10-20 9:41 ` Viresh Kumar
2020-10-20 9:52 ` Sudeep Holla
2020-10-20 9:59 ` Viresh Kumar
2020-10-27 22:24 ` Guenter Roeck
2020-10-28 4:06 ` Viresh Kumar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201019092411.b3znjxebay3puq2j@vireshk-i7 \
--to=viresh.kumar@linaro.org \
--cc=georgi.djakov@linaro.org \
--cc=gregkh@linuxfoundation.org \
--cc=kgene@kernel.org \
--cc=khilman@kernel.org \
--cc=krzk@kernel.org \
--cc=len.brown@intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=nks@flawful.org \
--cc=nm@ti.com \
--cc=pavel@ucw.cz \
--cc=rjw@rjwysocki.net \
--cc=sboyd@kernel.org \
--cc=stephan@gerhold.net \
--cc=sudeep.holla@arm.com \
--cc=ulf.hansson@linaro.org \
--cc=vincent.guittot@linaro.org \
--cc=vireshk@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).