linux-toradex.git/drivers/base/power/opp, branch master

PM / OPP: Move the OPP directory out of power/

2017-10-03T00:45:12+00:00

The drivers/base/power/ directory is special and contains code related
to power management core like system suspend/resume, hibernation, etc.
It was fine to keep the OPP code inside it when we had just one file for
it, but it is growing now and already has a directory for itself.

Lets move it directly under drivers/ directory, just like cpufreq and
cpuidle.

Signed-off-by: Viresh Kumar 
Acked-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Call notifier without holding opp_table->lock

2017-09-25T22:44:32+00:00

The notifier callbacks may want to call some OPP helper routines which
may try to take the same opp_table->lock again and cause a deadlock. One
such usecase was reported by Chanwoo Choi, where calling
dev_pm_opp_disable() leads us to the devfreq's OPP notifier handler,
which further calls dev_pm_opp_find_freq_floor() and it deadlocks.

We don't really need the opp_table->lock to be held across the notifier
call though, all we want to make sure is that the 'opp' doesn't get
freed while being used from within the notifier chain. We can do it with
help of dev_pm_opp_get/put() as well. Let's do it.

Cc: 4.11+  # 4.11+
Fixes: 5b650b388844 "PM / OPP: Take kref from _find_opp_table()"
Reported-by: Chanwoo Choi 
Tested-by: Chanwoo Choi 
Reviewed-by: Stephen Boyd 
Reviewed-by: Chanwoo Choi 
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Fix get sharing CPUs when hotplug is used

2017-08-01T12:10:55+00:00

We fail dev_pm_opp_of_get_sharing_cpus() when possible CPU device does
not exist. This can happen on platforms where not all possible CPUs
are available at start up ie. hotplugged out.  The CPU device is not
registered in the system so we are not able to check struct device to
set the sharing CPUs bitmask properly.

Example (real use case):
2 physical MIPS cores, 4 VPE, cpu0/2 run Linux and cpu1/3 are not
available for Linux at boot up. cpufreq-dt driver + OPP v2 fail to
register opp_table due to the fact there is no struct device for
cpu1 (remains offline at
bootup).

To solve the bug, stop using device struct to check device_node.
Instead get CPU device_node directly from device tree with
of_get_cpu_node().

Signed-off-by: Waldemar Rymarkiewicz 
Acked-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: OF: Use pr_debug() instead of pr_err() while adding OPP table

2017-07-16T00:24:33+00:00

Some platforms add the OPPs dynamically from platform specific drivers
instead of getting them statically from DT. The cpufreq-dt driver
already ignores the return value of dev_pm_opp_of_cpumask_add_table() to
not error out for such cases, but we still end up printing error message
from that routine. That's not nice.

Convert the print message to use pr_debug() instead.

Reported-by: Mason 
Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Add dev_pm_opp_{set|put}_clkname()

2017-06-23T23:41:55+00:00

In order to support OPP switching, OPP layer needs to get pointer to the
clock for the device. Simple cases work fine without using the routines
added by this patch (i.e.  by passing connection-id as NULL), but for a
device with multiple clocks available, the OPP core needs to know the
exact name of the clk to use.

Add a new set of APIs to get that done.

Tested-by: Rajendra Nayak 
Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Don't create debugfs "supply-0" directory unnecessarily

2017-06-22T01:15:30+00:00

We create "supply-0" debugfs directory even if the device doesn't do
voltage scaling. That looks confusing, as if the regulator is found but
we never managed to get voltage levels for it.

Avoid creating such a directory unnecessarily.

Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: opp-microvolt is not optional if regulators are set

2017-06-22T01:15:30+00:00

If dev_pm_opp_set_regulators() is called for a device and its regulators
are set in the OPP core, the OPP nodes for the device must contain the
"opp-microvolt" property, otherwise there is something wrong and we
better error out.

Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Don't create copy of regulators unnecessarily

2017-06-22T01:15:30+00:00

This code was required while the OPP core was managed with help of RCUs,
but not anymore. Get rid of unnecessary alloc/memcpy operations.

Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Reorganize _generic_set_opp_regulator()

2017-06-22T01:15:29+00:00

The code was overly complicated here because of the limitations that we
had with RCUs (Couldn't use opp-table and OPPs outside RCU protected
section and can't call sleep-able routines from within that). But that
is long gone now.

Reorganize _generic_set_opp_regulator() in order to avoid using "struct
dev_pm_set_opp_data" and copying data into it for the case where
opp_table->set_opp is not set.

Signed-off-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

PM / OPP: fix off-by-one bug in dev_pm_opp_get_max_volt_latency loop

2017-02-23T22:00:31+00:00

Reading array at given index before checking if index is valid results in
illegal memory access.

The bug was detected using KASAN framework.

Signed-off-by: Andrzej Hajda 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki