Commit Graph

168 Commits

Author SHA1 Message Date
Viresh Kumar
29b1a92e5e OPP: Handle all genpd cases together in _set_required_opps()
There is no real need of keeping separate code for single genpd case, it
can be made to work with a simple change.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2023-04-03 09:45:09 +05:30
Christophe JAILLET
d36cb843e4 OPP: Fix an un-initialized variable usage
smatch complains that 'ret' may be returned un-initialized.

Explicitly return 0 if we reach the end of the function (should
'opp_table->clk_count' be 0).

Fixes: 8174a3a613 ("OPP: Provide a simple implementation to configure multiple clocks")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-08-16 10:48:08 +05:30
Liang He
3466ea2cd6 OPP: Don't drop opp->np reference while it is still in use
The struct dev_pm_opp contains a reference of the DT node, opp->np,
throughout its lifetime. We should increase the refcount for the same
from _opp_add_static_v2(), and drop it while removing the OPP finally.

Signed-off-by: Liang He <windhl@126.com>
[ Viresh: Updated subject / commit log, create _of_clear_opp() and drop
	  reference from it]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-19 11:07:02 +05:30
Viresh Kumar
2f71ae1a9e OPP: Allow config_clks helper for single clk case
There is a corner case with Tegra30, where we want to skip clk
configuration via dev_pm_opp_set_opp(), but still want the OPP core to
read the "opp-hz" property so we can find the right OPP via freq finding
helpers.

This is the easiest of the ways to make it work, without any special
hacks in the OPP core. Allow config_clks to be passed for single clk
case.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-12 20:35:21 +05:30
Viresh Kumar
8174a3a613 OPP: Provide a simple implementation to configure multiple clocks
This provides a simple implementation to configure multiple clocks for a
device.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-12 20:35:21 +05:30
Viresh Kumar
f123ea7451 OPP: Assert clk_count == 1 for single clk helpers
Many helpers can be safely called only for devices that have a single
clk associated with them. Assert the same for those routines.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-12 20:35:20 +05:30
Viresh Kumar
e10a46443f OPP: Add key specific assert() method to key finding helpers
The helpers for the clock key, at least, would need to assert that the
helpers are called only for single clock case. Prepare for that by
adding an argument to the key finding helpers.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-12 20:35:20 +05:30
Viresh Kumar
274c3e83e7 OPP: Compare bandwidths for all paths in _opp_compare_key()
Replicate the same behavior as "rates" here and compare all values
instead of relying on the first entry alone.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-12 20:35:20 +05:30
Viresh Kumar
2083da24eb OPP: Allow multiple clocks for a device
This patch adds support to allow multiple clocks for a device.

The design is pretty much similar to how this is done for regulators,
and platforms can supply their own version of the config_clks() callback
if they have multiple clocks for their device. The core manages the
calls via opp_table->config_clks() eventually.

We have kept both "clk" and "clks" fields in the OPP table structure and
the reason is provided as a comment in _opp_set_clknames(). The same
isn't done for "rates" though and we use rates[0] at most of the places
now.

Co-developed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-12 20:35:20 +05:30
Viresh Kumar
1efae8d2e7 OPP: Make dev_pm_opp_set_opp() independent of frequency
dev_pm_opp_set_opp() can be called for any device, it may or may not
have a frequency value associated with it.

If a frequency value isn't available, we pass 0 to _set_opp(). Make it
optional instead by making _set_opp() accept a pointer instead, as the
frequency value is anyway available in the OPP. This makes
dev_pm_opp_set_opp() and _set_opp() completely independent of any
special key value.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:51 +05:30
Viresh Kumar
8bdac14b0c OPP: Reuse _opp_compare_key() in _opp_add_static_v2()
Reuse _opp_compare_key() in _opp_add_static_v2() instead of just
comparing frequency while finding suspend frequency. Also add a comment
over _opp_compare_key() explaining its return values.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:51 +05:30
Viresh Kumar
4768914bff OPP: Remove rate_not_available parameter to _opp_add()
commit 32715be4fe ("opp: Fix adding OPP entries in a wrong order if
rate is unavailable") removed the only user of this field, get rid of
rest of it now.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:50 +05:30
Viresh Kumar
d613458332 OPP: Use consistent names for OPP table instances
The OPP table is called "opp_table" at most of the places and "table" at
few. Make all of them follow the same naming convention, "opp_table".

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:50 +05:30
Viresh Kumar
add1dc094a OPP: Use generic key finding helpers for bandwidth key
Use the recently added generic key findings helpers to find bandwidth
key values.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:50 +05:30
Viresh Kumar
c2ab2cb637 OPP: Use generic key finding helpers for level key
Use the recently added generic key findings helpers to find level key
values.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:50 +05:30
Viresh Kumar
aab8ced221 OPP: Add generic key finding helpers and use them for freq APIs
There are three type of helpers, to find exact, ceil, and floor values,
replicated for multiple key types, freq, level, bw. And all of these
helpers share a lot of boilerplate code.

Add generic key finding helpers to reduce code redundancy.

Also update the freq finder helpers to use the new infrastructure.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:50 +05:30
Viresh Kumar
9fbb626056 OPP: Remove dev_pm_opp_find_freq_ceil_by_volt()
This was added few years back, but the code that was supposed to use it
never got merged. Remove the unused helper.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:50 +05:30
Viresh Kumar
1f378c6ead OPP: Remove custom OPP helper support
The only user of the custom helper is migrated to use
dev_pm_opp_set_config_regulators() interface. Remove the now unused
custom OPP helper support.

This cleans up _set_opp() and leaves a single code path to be used by
all users.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:50 +05:30
Viresh Kumar
69b1af178a OPP: Add dev_pm_opp_get_supplies()
We already have an API for getting voltage information for a single
regulator, dev_pm_opp_get_voltage(), but there is nothing available for
multiple regulator case.

This patch adds a new API, dev_pm_opp_get_supplies(), to get all
information related to the supplies for an OPP.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:49 +05:30
Viresh Kumar
c522ce8a08 OPP: Make _generic_set_opp_regulator() a config_regulators() interface
In order to reuse the same code path, i.e. clk_set_rate() from
_set_opp(), migrate _generic_set_opp_regulator() to implement a
config_regulators() interface.

It is renamed to _opp_config_regulator_single() and is set as the
preferred config_regulators() interface whenever we have a single
regulator available.

Note that this also drops code responsible for restoring the
voltage/freq in case of errors. We aren't handling that properly
currently, restoring only some of the resources while leaving others out
(like bandwidth and required OPPs). It is better to drop all of it
instead of partial restoration.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:49 +05:30
Viresh Kumar
aee3352f6e OPP: Add support for config_regulators() helper
Extend the dev_pm_opp_set_config() interface to allow adding
config_regulators() helpers. This helper will be called to set the
voltages of the regulators from the regular path in _set_opp(), while we
are trying to change the OPP.

This will eventually replace the custom set_opp() helper.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:49 +05:30
Viresh Kumar
298098e55a OPP: Migrate set-prop-name helper API to use set-config helpers
Now that we have a central API to handle all OPP table configurations,
migrate the set-prop-name family of helpers to use the new
infrastructure.

The return type and parameter to the APIs change a bit due to this,
update the current users as well in the same commit in order to avoid
breaking builds.

Acked-by: Samuel Holland <samuel@sholland.org> # sun50i
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:49 +05:30
Viresh Kumar
442e7a1786 OPP: Migrate attach-genpd API to use set-config helpers
Now that we have a central API to handle all OPP table configurations,
migrate the attach-genpd family of helpers to use the new
infrastructure.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:49 +05:30
Viresh Kumar
3c543b42a6 OPP: Migrate set-opp-helper API to use set-config helpers
Now that we have a central API to handle all OPP table configurations,
migrate the set-opp-helper family of helpers to use the new
infrastructure.

The return type and parameter to the APIs change a bit due to this,
update the current users as well in the same commit in order to avoid
breaking builds.

Remove devm_pm_opp_register_set_opp_helper() as it has no users
currently.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:49 +05:30
Viresh Kumar
2368f57685 OPP: Migrate set-clk-name API to use set-config helpers
Now that we have a central API to handle all OPP table configurations,
migrate the set-clk-name family of helpers to use the new
infrastructure.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:48 +05:30
Viresh Kumar
89f03984fa OPP: Migrate set-supported-hw API to use set-config helpers
Now that we have a central API to handle all OPP table configurations,
migrate the set-supported-hw family of helpers to use the new
infrastructure.

The return type and parameter to the APIs change a bit due to this,
update the current users as well in the same commit in order to avoid
breaking builds.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:48 +05:30
Viresh Kumar
b0ec094286 OPP: Migrate set-regulators API to use set-config helpers
Now that we have a central API to handle all OPP table configurations,
migrate the set-regulators family of helpers to use the new
infrastructure.

The return type and parameter to the APIs change a bit due to this,
update the current users as well in the same commit in order to avoid
breaking builds.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:33 +05:30
Viresh Kumar
11b9b66358 OPP: Add dev_pm_opp_set_config() and friends
The OPP core already have few configuration specific APIs and it is
getting complex or messy for both the OPP core and its users.

Lets introduce a new set of API which will be used for all kind of
different configurations, and shall eventually be used by all the
existing ones.

The new API, returns a unique token instead of a pointer to the OPP
table, which allows the OPP core to drop the resources selectively later
on.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:27:32 +05:30
Viresh Kumar
87686cc845 OPP: Make dev_pm_opp_set_regulators() accept NULL terminated list
Make dev_pm_opp_set_regulators() accept a NULL terminated list of names
instead of making the callers keep the two parameters in sync, which
creates an opportunity for bugs to get in.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Steven Price <steven.price@arm.com> # panfrost
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-07-08 11:26:44 +05:30
Viresh Kumar
0a43452bb6 OPP: Track if clock name is configured by platform
Track if the clock name is configured by the platform or not. This is a
preparatory change and will be used by later commits. This also makes
the behavior of the clkname API similar to other ones, which allow
repeated calls to the same API for each CPU.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-06-09 13:57:55 +05:30
Viresh Kumar
9bfb1ffff1 OPP: Fix typo in comment
Replace rate with state.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-06-09 13:57:55 +05:30
Yang Li
617df304f3 opp: Fix some kernel-doc comments
Make @freq to @bw in dev_pm_opp_find_bw_ceil() and
dev_pm_opp_find_bw_floor() kernel-doc comment to
remove warnings found by running scripts/kernel-doc,
which is caused by using 'make W=1'.

drivers/opp/core.c:753: warning: Function parameter or member 'bw' not
described in 'dev_pm_opp_find_bw_ceil'
drivers/opp/core.c:753: warning: Excess function parameter 'freq'
description in 'dev_pm_opp_find_bw_ceil'
drivers/opp/core.c:812: warning: Function parameter or member 'bw' not
described in 'dev_pm_opp_find_bw_floor'
drivers/opp/core.c:812: warning: Excess function parameter 'freq'
description in 'dev_pm_opp_find_bw_floor'

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-06-06 11:58:51 +05:30
Tang Bin
4ea9496cbc opp: Fix error check in dev_pm_opp_attach_genpd()
dev_pm_domain_attach_by_name() may return NULL in some cases,
so IS_ERR() doesn't meet the requirements. Thus fix it.

Fixes: 6319aee10e ("opp: Attach genpds to devices from within OPP core")
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
[ Viresh: Replace ENODATA with ENODEV ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-06-06 11:58:51 +05:30
Viresh Kumar
22079af7df opp: Reorder definition of ceil/floor helpers
Reorder the helpers to keep all freq specific ones, followed by level
and bw.

No functional change.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-05-04 15:40:22 +05:30
Krzysztof Kozlowski
00ce3873f7 opp: Add apis to retrieve opps with interconnect bandwidth
Add dev_pm_opp_find_bw_ceil and dev_pm_opp_find_bw_floor to retrieve opps
based on interconnect associated with the opp and bandwidth. The index
variable is the index of the interconnect as specified in the opp table
in Devicetree.

Co-developed-by: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-05-04 15:38:06 +05:30
Jakob Koschel
95073b721c opp: replace usage of found with dedicated list iterator variable
To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-04-11 08:31:09 +05:30
Krzysztof Kozlowski
543256d239 PM: opp: simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and the error value gets printed.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-04-11 08:23:21 +05:30
Lukasz Luba
4f9a7a1dc2 OPP: Add "opp-microwatt" supporting code
Add new property to the OPP: power value. The OPP entry in the DT can have
"opp-microwatt". Add the needed code to handle this new property in the
existing infrastructure.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2022-03-03 09:35:04 +05:30
Dmitry Osipenko
3734b9f2ce opp: Change type of dev_pm_opp_attach_genpd(names) argument
Elements of the 'names' array are not changed by the code, constify them
for consistency.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-10-04 14:38:59 +05:30
Marijn Suijten
19526d092c opp: core: Check for pending links before reading required_opp pointers
Commit 4fa82a87ba ("opp: Allow required-opps to be used for non genpd
use cases") dereferences the pointers in required_opp_tables but these
might be set to an ERR_PTR if the list still has lazy links pending,
resulting in segfaults.  Prior to this patch IS_ERR was also checked on
required_opp_tables[i] before reading ->is_genpd inside
_opp_table_alloc_required_tables, which is at the same time the
predicate to add this table to the lazy list.  This segfault is solved
by reordering the checks to bail on lazy pending tables before reading
->is_genpd.

Fixes: 4fa82a87ba ("opp: Allow required-opps to be used for non genpd use cases")
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-08-23 12:44:55 +05:30
Dmitry Osipenko
c3ddfe66d2 opp: Drop empty-table checks from _put functions
The current_opp is released only when whole OPP table is released,
otherwise it's only marked as removed by dev_pm_opp_remove_table().
Functions like dev_pm_opp_put_clkname() and dev_pm_opp_put_supported_hw()
are checking whether OPP table is empty and it's not if current_opp is
set since it holds the refcount of OPP, this produces a noisy warning
from these functions about busy OPP table. Remove the checks to fix it.

Cc: stable@vger.kernel.org
Fixes: 81c4d8a3c4 ("opp: Keep track of currently programmed OPP")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-08-16 09:42:08 +05:30
Hsin-Yi Wang
4fa82a87ba opp: Allow required-opps to be used for non genpd use cases
Don't limit required_opp_table to genpd only. One possible use case is
cpufreq based devfreq governor, which can use required-opps property to
derive devfreq from cpufreq.

Though the OPP core still doesn't support non-genpd required-opps in
_set_required_opps().

Suggested-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
[ Viresh: Update _set_required_opps() to check for genpd ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-06-18 09:00:55 +05:30
Dmitry Osipenko
9edf48a4bf opp: Change return type of devm_pm_opp_attach_genpd()
Make devm_pm_opp_attach_genpd() to return error code instead of
opp_table pointer in order to have return type consistent with the
other resource-managed OPP helpers.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-03-16 10:14:11 +05:30
Dmitry Osipenko
c41c8a3485 opp: Change return type of devm_pm_opp_register_set_opp_helper()
Make devm_pm_opp_register_set_opp_helper() to return error code instead
of opp_table pointer in order to have return type consistent with the
other resource-managed OPP helpers.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-03-16 10:14:11 +05:30
Yangtao Li
9c4f220f3d opp: Add devres wrapper for dev_pm_opp_set_supported_hw
Add devres wrapper for dev_pm_opp_set_supported_hw() to simplify drivers
code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-03-15 09:26:53 +05:30
Yangtao Li
32aee78bc5 opp: Add devres wrapper for dev_pm_opp_set_regulators
Add devres wrapper for dev_pm_opp_set_regulators() to simplify drivers
code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-03-15 09:26:53 +05:30
Yangtao Li
a74f681c37 opp: Add devres wrapper for dev_pm_opp_set_clkname
Add devres wrapper for dev_pm_opp_set_clkname() to simplify drivers code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-03-15 09:26:53 +05:30
Beata Michalska
606a5d4227 opp: Don't drop extra references to OPPs accidentally
We are required to call dev_pm_opp_put() from outside of the
opp_table->lock as debugfs removal needs to happen lock-less to avoid
circular dependency issues.

commit cf1fac943c ("opp: Reduce the size of critical section in
_opp_kref_release()") tried to fix that introducing a new routine
_opp_get_next() which keeps returning OPPs that can be freed by the
callers and this routine shall be called without holding the
opp_table->lock.

Though the commit overlooked the fact that the OPPs can be referenced by
other users as well and this routine will end up dropping references
which were taken by other users and hence freeing the OPPs prematurely.

In effect, other users of the OPPs will end up having invalid pointers
at hand. We didn't see any crash reports earlier as the exact situation
never happened, though it is certainly possible.

We need a way to mark which OPPs are no longer referenced by the OPP
core, so we don't drop extra references to them accidentally.

This commit adds another OPP flag, "removed", which is used to track
this. And now we should never end up dropping extra references to the
OPPs.

Cc: v5.11+ <stable@vger.kernel.org> # v5.11+
Fixes: cf1fac943c ("opp: Reduce the size of critical section in _opp_kref_release()")
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
[ Viresh: Almost rewrote entire patch, added new "removed" field,
	  rewrote commit log and added the correct Fixes tag. ]
Co-developed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-03-12 09:26:52 +05:30
Jonathan Marek
de04241ab8 opp: Don't skip freq update for different frequency
We skip the OPP update if the current and target OPPs are same. This is
fine for the devices that don't support frequency but may cause issues
for the ones that need to program frequency.

An OPP entry doesn't really signify a single operating frequency but
rather the highest frequency at which the other properties of the OPP
entry apply. And we may reach here with different frequency values,
while all of them would point to the same OPP entry in the OPP table.

We just need to update the clock frequency in that case, though in order
to not add special exit points we reuse the code flow from a normal
path.

While at it, rearrange the conditionals in the 'if' statement to check
'enabled' flag at the end.

Fixes: 81c4d8a3c4 ("opp: Keep track of currently programmed OPP")
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
[ Viresh: Improved commit log and subject, rename current_freq as
	  current_rate, document it, remove local variable and rearrange
	  code. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-02-18 12:31:08 +05:30
Saravana Kannan
7d8658ef65 OPP: Add function to look up required OPP's for a given OPP
Add a function that allows looking up required OPPs given a source OPP
table, destination OPP table and the source OPP.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
[ Viresh: Rearranged code, fixed return errors ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-02-04 16:30:14 +05:30