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Commit Graph

22 Commits

Author SHA1 Message Date
Viresh Kumar
09f662f953 OPP: Return error on error from dev_pm_opp_get_opp_count()
Return error number instead of 0 on failures.

Fixes: a1e8c13600 ("PM / OPP: "opp-hz" is optional for power domains")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-10-04 09:10:56 +05:30
Viresh Kumar
283d55e68d OPP: Prevent creating multiple OPP tables for devices sharing OPP nodes
When two or more devices are sharing their clock and voltage rails, they
share the same OPP table. But there are some corner cases where the OPP
core incorrectly creates separate OPP tables for them.

For example, CPU 0 and 1 share clock/voltage rails. The platform
specific code calls dev_pm_opp_set_regulators() for CPU0 and the OPP
core creates an OPP table for it (the individual OPPs aren't initialized
as of now). The same is repeated for CPU1 then. Because
_opp_get_opp_table() doesn't compare DT node pointers currently, it
fails to find the link between CPU0 and CPU1 and so creates a new OPP
table.

Fix this by calling _managed_opp() from _opp_get_opp_table().
_managed_opp() gain an additional argument (index) to get the right node
pointer. This resulted in simplifying code in _of_add_opp_table_v2() as
well.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-10-01 15:00:31 +05:30
Viresh Kumar
cdd6ed90cd OPP: Use a single mechanism to free the OPP table
Currently there are two separate ways to free the OPP table based on how
it is created in the first place.

We call _dev_pm_opp_remove_table() to free the static and/or dynamic
OPP, OPP list devices, etc. This is done for the case where the OPP
table is added while initializing the OPPs, like via the path
dev_pm_opp_of_add_table().

We also call dev_pm_opp_put_opp_table() in some cases which eventually
frees the OPP table structure once the reference count reaches 0. This
is used by the first case as well as other cases like
dev_pm_opp_set_regulators() where the OPPs aren't necessarily
initialized at this point.

This whole thing is a bit unclear and messy and obstruct any further
cleanup/fixup of OPP core.

This patch tries to streamline this by keeping a single path for OPP
table destruction, i.e. dev_pm_opp_put_opp_table().

All the cleanup happens in _opp_table_kref_release() now after the
reference count reaches 0. _dev_pm_opp_remove_table() is removed as it
isn't required anymore.

We don't drop the reference to the OPP table after creating it from
_of_add_opp_table_v{1|2}() anymore and the same is dropped only when we
try to remove them.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:46 -07:00
Viresh Kumar
2a4eb7358a OPP: Don't remove dynamic OPPs from _dev_pm_opp_remove_table()
Only one platform was depending on this feature and it is already
updated now. Stop removing dynamic OPPs from _dev_pm_opp_remove_table().
This simplifies lot of paths and removes unnecessary parameters.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:45 -07:00
Viresh Kumar
d0e8ae6c26 OPP: Create separate kref for static OPPs list
The static OPPs don't always get freed with the OPP table, it can happen
before that as well. For example, if the OPP table is first created
using helpers like dev_pm_opp_set_supported_hw() and the OPPs are
created at a later point. Now when the OPPs are removed, the OPP table
stays until the time dev_pm_opp_put_supported_hw() is called.

Later patches will streamline the freeing of OPP table and that requires
the static OPPs to get freed with help of a separate kernel reference.
This patch prepares for that by creating a separate kref for static OPPs
list.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:43 -07:00
Viresh Kumar
0ad8c62390 OPP: Don't take OPP table's kref for static OPPs
The reference count is only required to be incremented for every call
that may lead to adding the OPP table. For static OPPs the same should
be done from the parent routine which adds all static OPPs together and
so only one refcount for all static OPPs.

Update code to reflect that.

The refcount is incremented every time a dynamic OPP is created (as that
can lead to creating the OPP table) and the same is dropped when the OPP
is removed.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:43 -07:00
Viresh Kumar
eb7c8743d6 OPP: Pass index to _of_init_opp_table()
This is a preparatory patch required for the next commit which will
start using OPP table's node pointer in _of_init_opp_table(), which
requires the index in order to read the OPP table's phandle.

This commit adds the index argument in the call chains in order to get
it delivered to _of_init_opp_table().

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:41 -07:00
Viresh Kumar
3d2556992a OPP: Protect dev_list with opp_table lock
The dev_list needs to be protected with a lock, else we may have
simultaneous access (addition/removal) to it and that would be racy.
Extend scope of the opp_table lock to protect dev_list as well.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:40 -07:00
Waldemar Rymarkiewicz
c5c2a97b3a PM / OPP: Update voltage in case freq == old_freq
This commit fixes a rare but possible case when the clk rate is updated
without update of the regulator voltage.

At boot up, CPUfreq checks if the system is running at the right freq. This
is a sanity check in case a bootloader set clk rate that is outside of freq
table present with cpufreq core. In such cases system can be unstable so
better to change it to a freq that is preset in freq-table.

The CPUfreq takes next freq that is >= policy->cur and this is our
target_freq that needs to be set now.

dev_pm_opp_set_rate(dev, target_freq) checks the target_freq and the
old_freq (a current rate). If these are equal it returns early. If not,
it searches for OPP (old_opp) that fits best to old_freq (not listed in
the table) and updates old_freq (!).

Here, we can end up with old_freq = old_opp.rate = target_freq, which
is not handled in _generic_set_opp_regulator(). It's supposed to update
voltage only when freq > old_freq  || freq > old_freq.

if (freq > old_freq) {
		ret = _set_opp_voltage(dev, reg, new_supply);
[...]
if (freq < old_freq) {
		ret = _set_opp_voltage(dev, reg, new_supply);
		if (ret)

It results in, no voltage update while clk rate is updated.

Example:
freq-table = {
	1000MHz   1.15V
	 666MHZ   1.10V
	 333MHz   1.05V
}
boot-up-freq        = 800MHz   # not listed in freq-table
freq = target_freq  = 1GHz
old_freq            = 800Mhz
old_opp = _find_freq_ceil(opp_table, &old_freq);  #(old_freq is modified!)
old_freq            = 1GHz

Fixes: 6a0712f6f1 ("PM / OPP: Add dev_pm_opp_set_rate()")
Cc: 4.6+ <stable@vger.kernel.org> # v4.6+
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-06-19 15:53:32 +05:30
Viresh Kumar
5019acc693 PM / OPP: Fix shared OPP table support in dev_pm_opp_register_set_opp_helper()
It should be fine to call dev_pm_opp_register_set_opp_helper() for all
possible CPUs, even if some of them share the OPP table as the caller
may not be aware of sharing policy.

Lets increment the reference count of the OPP table and return its
pointer. The caller need to call dev_pm_opp_register_put_opp_helper()
the same number of times later on to drop all the references.

To avoid adding another counter to count how many times
dev_pm_opp_register_set_opp_helper() is called for the same OPP table,
dev_pm_opp_register_put_opp_helper() frees the resources on the very
first call made to it, assuming that the caller would be calling it
sequentially for all the CPUs. We can revisit that if that assumption is
broken in the future.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-05-22 17:00:10 +05:30
Viresh Kumar
779b783cfa PM / OPP: Fix shared OPP table support in dev_pm_opp_set_regulators()
It should be fine to call dev_pm_opp_set_regulators() for all possible
CPUs, even if some of them share the OPP table as the caller may not be
aware of sharing policy.

Lets increment the reference count of the OPP table and return its
pointer. The caller need to call dev_pm_opp_put_regulators() the same
number of times later on to drop all the references.

To avoid adding another counter to count how many times
dev_pm_opp_set_regulators() is called for the same OPP table,
dev_pm_opp_put_regulators() frees the resources on the very first call
made to it, assuming that the caller would be calling it sequentially
for all the CPUs. We can revisit that if that assumption is broken in
the future.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-05-22 17:00:10 +05:30
Viresh Kumar
878ec1a9f0 PM / OPP: Fix shared OPP table support in dev_pm_opp_set_prop_name()
It should be fine to call dev_pm_opp_set_prop_name() for all possible
CPUs, even if some of them share the OPP table as the caller may not be
aware of sharing policy.

Lets increment the reference count of the OPP table and return its
pointer. The caller need to call dev_pm_opp_put_prop_name() the same
number of times later on to drop all the references.

To avoid adding another counter to count how many times
dev_pm_opp_set_prop_name() is called for the same OPP table,
dev_pm_opp_put_prop_name() frees the resources on the very first call
made to it, assuming that the caller would be calling it sequentially
for all the CPUs. We can revisit that if that assumption is broken in
the future.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-05-22 17:00:10 +05:30
Viresh Kumar
25419de1b8 PM / OPP: Fix shared OPP table support in dev_pm_opp_set_supported_hw()
It should be fine to call dev_pm_opp_set_supported_hw() for all possible
CPUs, even if some of them share the OPP table as the caller may not be
aware of sharing policy.

Lets increment the reference count of the OPP table and return its
pointer. The caller need to call dev_pm_opp_put_supported_hw() the same
number of times later on to drop all the references.

To avoid adding another counter to count how many times
dev_pm_opp_set_supported_hw() is called for the same OPP table,
dev_pm_opp_put_supported_hw() frees the resources on the very first call
made to it, assuming that the caller would be calling it sequentially
for all the CPUs. We can revisit that if that assumption is broken in
the future.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-05-22 17:00:09 +05:30
Viresh Kumar
28fa4aca26 PM / OPP: Remove dev_pm_opp_{un}register_get_pstate_helper()
These helpers aren't used anymore, remove them.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2018-05-09 10:15:21 +05:30
Viresh Kumar
3ba98324e8 PM / OPP: Get performance state using genpd helper
The genpd core provides an API now to retrieve the performance state
from DT, use that instead of the ->get_pstate() callback.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2018-05-09 10:15:20 +05:30
Viresh Kumar
a88bd2a51e PM / OPP: Implement of_dev_pm_opp_find_required_opp()
A device's DT node or its OPP nodes can contain a phandle to other
device's OPP node, in the "required-opps" property.

This patch implements a routine to find that required OPP from the node
that contains the "required-opps" property.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2018-05-09 10:15:19 +05:30
Viresh Kumar
a1e8c13600 PM / OPP: "opp-hz" is optional for power domains
"opp-hz" property is optional for power domains now and we shouldn't
error out if it is missing for power domains.

This patch creates two new routines, _get_opp_count() and
_opp_is_duplicate(), by separating existing code from their parent
functions. Also skip duplicate OPP check for power domain OPPs as they
may not have any the "opp-hz" field, but a platform specific performance
state binding to uniquely identify OPP nodes.

By default the debugfs OPP nodes are named using the "rate" value, but
that isn't possible for the power domain OPP nodes and hence they use
the index of the OPP node in the OPP node list instead.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2018-05-09 10:15:18 +05:30
Viresh Kumar
b6aa98364f PM / OPP: Add dev_pm_opp_{un}register_get_pstate_helper()
This adds the dev_pm_opp_{un}register_get_pstate_helper() helper
routines which will be used to set the get_pstate() callback for a
device. This callback will be later called internally by the OPP core to
get performance state corresponding to an OPP.

This is required temporarily until the time we have proper DT bindings
to include the performance state information.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-14 00:54:41 +02:00
Viresh Kumar
009acd196f PM / OPP: Support updating performance state of device's power domain
The genpd framework now provides an API to request device's power
domain to update its performance state.  Use that interface from the
OPP core for devices whose power domains support performance states.

Note that this commit doesn't add any mechanism by which performance
states are made available to the OPP core. That would be done by a
later commit.

Note that the current implementation is restricted to the case where
the device doesn't have separate regulators for itself. We shouldn't
over engineer the code before we have real use case for them. We can
always come back and add more code to support such cases later on.

Tested-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-14 00:54:40 +02:00
Viresh Kumar
604a7aeb43 PM / OPP: Rename dev_pm_opp_register_put_opp_helper()
The routine is named incorrectly since the first attempt as there is
nothing like a put_opp() helper. We wanted to unregister the set_opp()
helper here and so it should rather be named as
dev_pm_opp_unregister_set_opp_helper().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-11 01:54:18 +02:00
Fabio Estevam
035ed07208 PM / OPP: Move error message to debug level
On some i.MX6 platforms which do not have speed grading
check, opp table will not be created in platform code,
so cpufreq driver prints the following error message:

cpu cpu0: dev_pm_opp_get_opp_count: OPP table not found (-19)

However, this is not really an error in this case because the
imx6q-cpufreq driver first calls dev_pm_opp_get_opp_count()
and if it fails, it means that platform code does not provide
OPP and then dev_pm_opp_of_add_table() will be called.

In order to avoid such confusing error message, move it to
debug level.

It is up to the caller of dev_pm_opp_get_opp_count() to check its
return value and decide if it will print an error or not.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-11 01:51:15 +02:00
Viresh Kumar
7813dd6fc7 PM / OPP: Move the OPP directory out of power/
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 <viresh.kumar@linaro.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-03 02:45:12 +02:00