linux-stable.git/drivers/opp/core.c, branch linux-5.4.y

OPP: Fix passing 0 to PTR_ERR in _opp_attach_genpd()

2023-09-23T08:59:40+00:00

[ Upstream commit d920920f85a82c1c806a4143871a0e8f534732f2 ]

If dev_pm_domain_attach_by_name() returns NULL, then 0 will be passed to
PTR_ERR() as reported by the smatch warning below:

drivers/opp/core.c:2456 _opp_attach_genpd() warn: passing zero to 'PTR_ERR'

Fix it by checking for the non-NULL virt_dev pointer before passing it to
PTR_ERR. Otherwise return -ENODEV.

Fixes: 4ea9496cbc95 ("opp: Fix error check in dev_pm_opp_attach_genpd()")
Signed-off-by: Manivannan Sadhasivam 
Signed-off-by: Viresh Kumar 
Signed-off-by: Sasha Levin

opp: Fix error check in dev_pm_opp_attach_genpd()

2022-08-25T09:18:00+00:00

[ Upstream commit 4ea9496cbc959eb5c78f3e379199aca9ef4e386b ]

dev_pm_domain_attach_by_name() may return NULL in some cases,
so IS_ERR() doesn't meet the requirements. Thus fix it.

Fixes: 6319aee10e53 ("opp: Attach genpds to devices from within OPP core")
Signed-off-by: Tang Bin 
[ Viresh: Replace ENODATA with ENODEV ]
Signed-off-by: Viresh Kumar 
Signed-off-by: Sasha Levin

opp: Reduce the size of critical section in _opp_table_kref_release()

2020-11-18T18:20:21+00:00

[ Upstream commit e0df59de670b48a923246fae1f972317b84b2764 ]

There is a lot of stuff here which can be done outside of the big
opp_table_lock, do that. This helps avoiding few circular dependency
lockdeps around debugfs and interconnects.

Reported-by: Rob Clark 
Reported-by: Dmitry Osipenko 
Signed-off-by: Viresh Kumar 
Signed-off-by: Sasha Levin

opp: Prevent memory leak in dev_pm_opp_attach_genpd()

2020-10-29T08:58:06+00:00

[ Upstream commit cb60e9602cce1593eb1e9cdc8ee562815078a354 ]

If dev_pm_opp_attach_genpd() is called multiple times (once for each CPU
sharing the table), then it would result in unwanted behavior like
memory leak, attaching the domain multiple times, etc.

Handle that by checking and returning earlier if the domains are already
attached. Now that dev_pm_opp_detach_genpd() can get called multiple
times as well, we need to protect that too.

Note that the virtual device pointers aren't returned in this case, as
they may become unavailable to some callers during the middle of the
operation.

Reported-by: Stephan Gerhold 
Signed-off-by: Viresh Kumar 
Signed-off-by: Sasha Levin

opp: Replace list_kref with a local counter

2020-10-01T11:17:26+00:00

[ Upstream commit 03758d60265c773e1d06d436b99ee338f2ac55d6 ]

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 
Signed-off-by: Sasha Levin

opp: Enable resources again if they were disabled earlier

2020-08-26T08:40:53+00:00

[ Upstream commit a4501bac0e553bed117b7e1b166d49731caf7260 ]

dev_pm_opp_set_rate() can now be called with freq = 0 in order
to either drop performance or bandwidth votes or to disable
regulators on platforms which support them.

In such cases, a subsequent call to dev_pm_opp_set_rate() with
the same frequency ends up returning early because 'old_freq == freq'

Instead make it fall through and put back the dropped performance
and bandwidth votes and/or enable back the regulators.

Cc: v5.3+  # v5.3+
Fixes: cd7ea582866f ("opp: Make dev_pm_opp_set_rate() handle freq = 0 to drop performance votes")
Reported-by: Sajida Bhanu 
Reviewed-by: Sibi Sankar 
Reported-by: Matthias Kaehlcke 
Tested-by: Matthias Kaehlcke 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rajendra Nayak 
[ Viresh: Don't skip clk_set_rate() and massaged changelog ]
Signed-off-by: Viresh Kumar 
Signed-off-by: Sasha Levin

opp: core: Revert "add regulators enable and disable"

2019-10-21T02:28:12+00:00

All the drivers, which use the OPP framework control regulators, which
are already enabled. Typically those regulators are also system critical,
due to providing power to CPU core or system buses. It turned out that
there are cases, where calling regulator_enable() on such boot-enabled
regulator has side-effects and might change its initial voltage due to
performing initial voltage balancing without all restrictions from the
consumers. Until this issue becomes finally solved in regulator core,
avoid calling regulator_enable()/disable() from the OPP framework.

This reverts commit 7f93ff73f7c8c8bfa6be33bcc16470b0b44682aa.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Mark Brown 
Signed-off-by: Viresh Kumar

opp: core: add regulators enable and disable

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

Add enable regulators to dev_pm_opp_set_regulators() and disable
regulators to dev_pm_opp_put_regulators(). Even if bootloader
leaves regulators enabled, they should be enabled in kernel in
order to increase the reference count.

Signed-off-by: Kamil Konieczny 
Signed-off-by: Viresh Kumar

opp: Don't decrement uninitialized list_kref

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

The list_kref was added for static OPPs and to track their users. The
kref is initialized while the static OPPs are added, but removed
unconditionally even if the static OPPs were never added. This causes
refcount mismatch warnings currently.

Fix that by always initializing the kref when the OPP table is first
initialized. The refcount is later incremented only for the second user
onwards.

Fixes: d0e8ae6c26da ("OPP: Create separate kref for static OPPs list")
Reported-by: Rajendra Nayak 
Signed-off-by: Viresh Kumar

opp: Add dev_pm_opp_find_level_exact()

2019-07-26T07:54:59+00:00

Since the performance states in the OPP table are unique, implement a
dev_pm_opp_find_level_exact() in order to be able to fetch a specific OPP.

Signed-off-by: Niklas Cassel 
[ Viresh: Updated commit log ]
Signed-off-by: Viresh Kumar