linux-stable.git/drivers/opp/of.c, branch v5.8

opp: Increase parsed_static_opps in _of_add_opp_table_v1()

2020-07-16T03:20:54+00:00

Currently, when using _of_add_opp_table_v2 parsed_static_opps is
increased and this value is used in _opp_remove_all_static() to
check if there are static opp entries that need to be freed.
Unfortunately this does not happen when using _of_add_opp_table_v1(),
which leads to warnings.

This patch increases parsed_static_opps in _of_add_opp_table_v1() in a
similar way as in _of_add_opp_table_v2().

Fixes: 03758d60265c ("opp: Replace list_kref with a local counter")
Cc: v5.6+  # v5.6+
Signed-off-by: Walter Lozano 
[ Viresh: Do the operation with lock held and set the value to 1 instead
	  of incrementing it ]
Signed-off-by: Viresh Kumar

opp: Don't parse icc paths unnecessarily

2020-06-01T07:40:15+00:00

The DT node of the device may contain interconnect paths while the OPP
table doesn't have the bandwidth values. There is no need to parse the
paths in such cases.

Signed-off-by: Sibi Sankar 
Tested-by: Sibi Sankar 
Reviewed-by: Sibi Sankar 
[ Viresh: Support the case of !opp_table and massaged changelog ]
Signed-off-by: Viresh Kumar

opp: Add sanity checks in _read_opp_key()

2020-05-29T04:45:08+00:00

When we read the OPP keys, it would be nice to do some sanity checks
of the values we get from DT and see if they match with the information
that is populated in the OPP table. Let's pass a pointer of the table,
so that we can do some validation.

Signed-off-by: Georgi Djakov 
Reviewed-by: Matthias Kaehlcke 
Reviewed-by: Sibi Sankar 
[ Viresh: Fix rebase conflicts ]
Signed-off-by: Viresh Kumar

opp: Add support for parsing interconnect bandwidth

2020-05-29T04:45:08+00:00

The OPP bindings now support bandwidth values, so add support to parse it
from device tree and store it into the new dev_pm_opp_icc_bw struct, which
is part of the dev_pm_opp.

Signed-off-by: Georgi Djakov 
Reviewed-by: Matthias Kaehlcke 
[ Viresh: Create _read_bw() and use it, renamed _of_find_icc_paths() to
	  dev_pm_opp_of_find_icc_paths(), exported it and made opp_table
	  argument optional. Also drop the depends on from Kconfig. ]
Signed-off-by: Viresh Kumar

OPP: Add helpers for reading the binding properties

2020-05-13T06:18:13+00:00

The opp-hz DT property is not mandatory and we may use another property
as a key in the OPP table. Add helper functions to simplify the reading
and comparing the keys.

Signed-off-by: Saravana Kannan 
Signed-off-by: Georgi Djakov 
Reviewed-by: Matthias Kaehlcke 
Reviewed-by: Sibi Sankar 
[ Viresh: Removed an unnecessary comment ]
Signed-off-by: Viresh Kumar

opp: Replace list_kref with a local counter

2019-12-10T10:27:00+00:00

A kref or refcount isn't the right tool to be used here for counting
number of devices that are sharing the static OPPs created for the OPP
table. For example, we are reinitializing the kref again, after it
reaches a value of 0 and frees the resources, if the static OPPs get
added for the same OPP table structure (as the OPP table structure was
never freed). That is messy and very unclear.

This patch makes parsed_static_opps an unsigned integer and uses it to
count the number of users of the static OPPs. The increment and
decrement to parsed_static_opps is done under opp_table->lock now to
make sure no races are possible if the OPP table is getting added and
removed in parallel (which doesn't happen in practice, but can in
theory).

Signed-off-by: Viresh Kumar

opp: Free static OPPs on errors while adding them

2019-12-10T10:26:56+00:00

The static OPPs aren't getting freed properly, if errors occur while
adding them. Fix that by calling _put_opp_list_kref() and putting their
reference on failures.

Fixes: 11e1a1648298 ("opp: Don't decrement uninitialized list_kref")
Signed-off-by: Viresh Kumar

opp: Reinitialize the list_kref before adding the static OPPs again

2019-10-23T05:28:44+00:00

The list_kref reaches a count of 0 when all the static OPPs are removed,
for example when dev_pm_opp_of_cpumask_remove_table() is called, though
the actual OPP table may not get freed as it may still be referenced by
other parts of the kernel, like from a call to
dev_pm_opp_set_supported_hw(). And if we call
dev_pm_opp_of_cpumask_add_table() again at this point, we must
reinitialize the list_kref otherwise the kernel will hit a WARN() in
kref infrastructure for incrementing a kref with value 0.

Fixes: 11e1a1648298 ("opp: Don't decrement uninitialized list_kref")
Reported-by: Dmitry Osipenko 
Tested-by: Dmitry Osipenko 
Signed-off-by: Viresh Kumar

opp: of: drop incorrect lockdep_assert_held()

2019-10-10T10:46:13+00:00

_find_opp_of_np() doesn't traverse the list of OPP tables but instead
just the entries within an OPP table and so only requires to lock the
OPP table itself.

The lockdep_assert_held() was added there by mistake and isn't really
required.

Fixes: 5d6d106fa455 ("OPP: Populate required opp tables from "required-opps" property")
Cc: v5.0+  # v5.0+
Reported-by: Niklas Cassel 
Signed-off-by: Viresh Kumar

opp: of: Support multiple suspend OPPs defined in DT

2019-07-26T07:55:52+00:00

With property "opp-supported-hw" introduced, the OPP table
in DT could be a large OPP table and ONLY a subset of OPPs
are available, based on the version of the hardware running
on. That introduces restriction of using "opp-suspend"
property to define the suspend OPP, as we are NOT sure if the
OPP containing "opp-suspend" property is available for the
hardware running on, and the of opp core does NOT allow multiple
suspend OPPs defined in DT OPP table.

To eliminate this restrition, make of opp core allow multiple
suspend OPPs defined in DT, and pick the OPP with highest rate
and with "opp-suspend" property present to be suspend OPP, it
can speed up the suspend/resume process.

Signed-off-by: Anson Huang 
Signed-off-by: Viresh Kumar