| Message ID | 1380634382-15609-4-git-send-email-Sudeep.KarkadaNagesha@arm.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
On 1 October 2013 19:03, Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com> wrote: > From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> > > CPUs are registered as devices and their OPPs can be initialised from > the device tree. Whenever CPUs are hotplugged out, the corresponding > cpu devices are not removed. As a result all their OPPs remain intact > even when they are offlined. > > But when they are hotplugged back-in, the cpufreq along with other cpu > related subsystem gets re-initialised. Since its almost same as secondary > cpu being brought up, no special consideration is taken in the hotplug > path. This may result in cpufreq trying to initialise the OPPs again though > the cpu device already contains the OPPs. > > This patch checks if there exist an OPP list associated with the device, > before attempting to initialise it. > > Cc: Nishanth Menon <nm@ti.com> > Cc: "Rafael J. Wysocki" <rjw@sisk.pl> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> > --- > drivers/base/power/opp.c | 6 ++++++ > 1 file changed, 6 insertions(+) Acked-by: Viresh Kumar <viresh.kumar@linaro.org> -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 10/01/2013 08:33 AM, Sudeep KarkadaNagesha wrote: > From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> > > CPUs are registered as devices and their OPPs can be initialised from > the device tree. Whenever CPUs are hotplugged out, the corresponding > cpu devices are not removed. As a result all their OPPs remain intact > even when they are offlined. > > But when they are hotplugged back-in, the cpufreq along with other cpu > related subsystem gets re-initialised. Since its almost same as secondary > cpu being brought up, no special consideration is taken in the hotplug > path. This may result in cpufreq trying to initialise the OPPs again though > the cpu device already contains the OPPs. > > This patch checks if there exist an OPP list associated with the device, > before attempting to initialise it. > > Cc: Nishanth Menon <nm@ti.com> > Cc: "Rafael J. Wysocki" <rjw@sisk.pl> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> > --- > drivers/base/power/opp.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c > index bb6ff64..05b2ebf 100644 > --- a/drivers/base/power/opp.c > +++ b/drivers/base/power/opp.c > @@ -709,9 +709,15 @@ int of_init_opp_table(struct device *dev) > { > const struct property *prop; > struct device_node *opp_node; > + struct device_opp *dev_opp; > const __be32 *val; > int nr; > > + /* Check for existing list for 'dev' */ > + dev_opp = find_device_opp(dev); > + if (!IS_ERR(dev_opp)) > + return -EEXIST; /* Device OPP already initialized */ in the interest of remaining code, Prefer comments not inline with code -> example if additional logic gets added later on in the if condition, someone'd have to move that comment over, instead, prefer it embedded before the if check as a line of it's own. > + > opp_node = of_parse_phandle(dev->of_node, > "operating-points-phandle", 0); > if (!opp_node) /* if no OPP phandle, search for OPPs in current node */ > other than that, Acked-by: Nishanth Menon <nm@ti.com>
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index bb6ff64..05b2ebf 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -709,9 +709,15 @@ int of_init_opp_table(struct device *dev) { const struct property *prop; struct device_node *opp_node; + struct device_opp *dev_opp; const __be32 *val; int nr; + /* Check for existing list for 'dev' */ + dev_opp = find_device_opp(dev); + if (!IS_ERR(dev_opp)) + return -EEXIST; /* Device OPP already initialized */ + opp_node = of_parse_phandle(dev->of_node, "operating-points-phandle", 0); if (!opp_node) /* if no OPP phandle, search for OPPs in current node */