On Fri, Nov 25, 2016 at 7:55 AM, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote: > On 25-11-16, 12:23, Viresh Kumar wrote: >> Joonyoung Shim reported an interesting problem on his ARM octa-core >> Odoroid-XU3 platform. During system suspend, dev_pm_opp_put_regulator() >> was failing for a struct device for which dev_pm_opp_set_regulator() is >> called earlier. >> >> This happened because an earlier call to >> dev_pm_opp_of_cpumask_remove_table() function (from cpufreq-dt.c file) >> removed all the entries from opp_table->dev_list apart from the last CPU >> device in the cpumask of CPUs sharing the OPP. >> >> But both dev_pm_opp_set_regulator() and dev_pm_opp_put_regulator() >> routines get CPU device for the first CPU in the cpumask. And so the OPP >> core failed to find the OPP table for the struct device. >> >> This patch attempts to fix this problem by adding another field in the >> struct opp_device: inactive. >> >> Instead of removing the entries from the list during >> dev_pm_opp_of_cpumask_remove_table() function call, we mark them as >> inactive. Such inactive devices will not be used by the core in most of >> the cases, like before, but will be used only at special places which >> need to take inactive devices into account. >> >> All the devices are removed from the list together now and that happens >> only when the opp_table gets destroyed. >> >> This patch is tested on Dual A15, Exynos5250 platform by compiling the >> cpufreq-dt driver as a module. The module is inserted/removed multiple >> times with combinations of CPU offline/online steps. >> >> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> > > @Rafael: Can you please add following while applying the patch ? > > Cc: <stable@xxxxxxxxxxxxxxx> # v4.4+ Yes, I can, but I need an ACK for this from Stephen too. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html