Re: [PATCH] opp: Return genpd virtual devices from dev_pm_opp_attach_genpd()

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Niklas Cassel <niklas.cassel@linaro.org>
Cc: Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
	Stephen Boyd <sboyd@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	linux-pm@vger.kernel.org,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Rajendra Nayak <rnayak@codeaurora.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] opp: Return genpd virtual devices from dev_pm_opp_attach_genpd()
Date: Wed, 17 Jul 2019 08:22:17 +0530	[thread overview]
Message-ID: <20190717025217.ne5tf2le2lj7oxbf@vireshk-i7> (raw)
In-Reply-To: <20190716104354.GA13780@centauri>

On 16-07-19, 12:43, Niklas Cassel wrote:
> On Mon, Jul 08, 2019 at 11:30:11AM +0530, Viresh Kumar wrote:
> > The cpufreq drivers don't need to do runtime PM operations on the
> > virtual devices returned by dev_pm_domain_attach_by_name() and so the
> > virtual devices weren't shared with the callers of
> > dev_pm_opp_attach_genpd() earlier.
> > 
> > But the IO device drivers would want to do that. This patch updates the
> > prototype of dev_pm_opp_attach_genpd() to accept another argument to
> > return the pointer to the array of genpd virtual devices.
> > 
> > Reported-by: Rajendra Nayak <rnayak@codeaurora.org>
> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > ---
> > @Rajendra: Can you please test this one ? I have only compile tested it.
> > 
> >  drivers/opp/core.c     | 5 ++++-
> >  include/linux/pm_opp.h | 4 ++--
> >  2 files changed, 6 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> > index 2958cc7bbb58..07b6f1187b3b 100644
> > --- a/drivers/opp/core.c
> > +++ b/drivers/opp/core.c
> > @@ -1775,6 +1775,7 @@ static void _opp_detach_genpd(struct opp_table *opp_table)
> >   * dev_pm_opp_attach_genpd - Attach genpd(s) for the device and save virtual device pointer
> >   * @dev: Consumer device for which the genpd is getting attached.
> >   * @names: Null terminated array of pointers containing names of genpd to attach.
> > + * @virt_devs: Pointer to return the array of virtual devices.
> >   *
> >   * Multiple generic power domains for a device are supported with the help of
> >   * virtual genpd devices, which are created for each consumer device - genpd
> > @@ -1789,7 +1790,8 @@ static void _opp_detach_genpd(struct opp_table *opp_table)
> >   * This helper needs to be called once with a list of all genpd to attach.
> >   * Otherwise the original device structure will be used instead by the OPP core.
> >   */
> > -struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names)
> > +struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
> > +		const char **names, struct device ***virt_devs)
> >  {
> >  	struct opp_table *opp_table;
> >  	struct device *virt_dev;
> > @@ -1850,6 +1852,7 @@ struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names
> >  		name++;
> >  	}
> >  
> > +	*virt_devs = opp_table->genpd_virt_devs;
> 
> Could we perhaps only do this if (virt_devs), that way callers can send in
> NULL if they don't care about the genpd virtual devices.

That was the idea and I failed to add it :(

-- 
viresh