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| author | Viresh Kumar <viresh.kumar@linaro.org> | 2019-10-18 14:11:58 +0530 |
|---|---|---|
| committer | Viresh Kumar <viresh.kumar@linaro.org> | 2019-10-23 10:58:44 +0530 |
| commit | b19c23551be8de0d4e59fe6af70f10763e3cc595 (patch) | |
| tree | 12a60bb2437dd98fcf9bca3f78e132ec4e0d0a7e /drivers/opp | |
| parent | 24957db1004353346583c9cc6d783db8f213e3ad (diff) | |
| download | lwn-b19c23551be8de0d4e59fe6af70f10763e3cc595.tar.gz lwn-b19c23551be8de0d4e59fe6af70f10763e3cc595.zip | |
opp: Reinitialize the list_kref before adding the static OPPs again
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 <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Diffstat (limited to 'drivers/opp')
| -rw-r--r-- | drivers/opp/of.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/opp/of.c b/drivers/opp/of.c index 6dc41faf74b5..1cbb58240b80 100644 --- a/drivers/opp/of.c +++ b/drivers/opp/of.c @@ -663,6 +663,13 @@ static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table) return 0; } + /* + * Re-initialize list_kref every time we add static OPPs to the OPP + * table as the reference count may be 0 after the last tie static OPPs + * were removed. + */ + kref_init(&opp_table->list_kref); + /* We have opp-table node now, iterate over it and add OPPs */ for_each_available_child_of_node(opp_table->np, np) { opp = _opp_add_static_v2(opp_table, dev, np); |