On 9 June 2017 at 18:16, Krzysztof Kozlowski <[email protected]> wrote:
> On Fri, Jun 09, 2017 at 06:08:47PM +0200, Krzysztof Kozlowski wrote:
>> The pm_genpd_present() iterates over list of domains so grabbing a
>> gpd_list_lock mutex is necessary before calling it. Otherwise we could
>> end up in iterating over and modifying the list at the same time.
>>
>> Signed-off-by: Krzysztof Kozlowski <[email protected]>
>> ---
>> drivers/base/power/domain.c | 7 ++++++-
>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
>> index 2e8d0f423507..2a6935dc0164 100644
>> --- a/drivers/base/power/domain.c
>> +++ b/drivers/base/power/domain.c
>> @@ -1099,8 +1099,13 @@ static void genpd_syscore_switch(struct device *dev,
>> bool suspend)
>> struct generic_pm_domain *genpd;
>>
>> genpd = dev_to_genpd(dev);
Actually there may be potential problem here as we may end up trying
to use the container_of() call for a PM domain, not being a genpd but
something else.
>> - if (!pm_genpd_present(genpd))
>> +
>> + mutex_lock(&gpd_list_lock);
>> + if (!pm_genpd_present(genpd)) {
>> + mutex_unlock(&gpd_list_lock);
>> return;
>> + }
>> + mutex_unlock(&gpd_list_lock);
Perhaps convert the hole thing above to call genpd_lookup_dev() instead?
>
> Eh, I might be too fast as this is not executed on my platform. The
> genpd_syscore_switch() seems to be called by clocksource_suspend() which
> is called by syscore ops. Should be safe but actually not tested.
>
> Someone with SH hardware is needed...
>
> Best regards,
> Krzysztof
>
Kind regards
Uffe
