Messages in this thread | | | Subject | Re: [PATCH 1/2] Revert "drivers: qcom: rpmh-rsc: Use rcuidle tracepoints for rpmh" | From | Maulik Shah <> | Date | Sat, 22 Aug 2020 21:51:40 +0530 |
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Hi,
On 8/19/2020 11:34 PM, Stephen Boyd wrote: > Quoting Maulik Shah (2020-08-19 03:07:49) >> This change was done based on an test results of unmerged series of >> adding RSC power domain and using .power_off callback of genpd to >> invoke rpmh_flush(). > Perhaps: > > Commit efde2659b0fe ("drivers: qcom: rpmh-rsc: Use rcuidle tracepoints > for rpmh") was written to fix a bug seen in an unmerged series that > implemented a struct generic_pm_domain::power_off() callback calling > rpmh_flush(). See stack trace below. Sure i will update in v2. > >> Call trace: >> dump_backtrace+0x0/0x174 >> show_stack+0x20/0x2c >> dump_stack+0xc8/0x124 >> lockdep_rcu_suspicious+0xe4/0x104 >> __tcs_buffer_write+0x230/0x2d0 >> rpmh_rsc_write_ctrl_data+0x210/0x270 >> rpmh_flush+0x84/0x24c >> rpmh_domain_power_off+0x78/0x98 >> _genpd_power_off+0x40/0xc0 >> genpd_power_off+0x168/0x208 >> >> Later the final merged solution is to use CPU PM notification to invoke >> rpmh_flush() and .power_off callback of genpd is not implemented in the >> driver. > I'd also add: > > CPU PM notifiers are run with RCU enabled/watching (see cpu_pm_notify() > and how it calls rcu_irq_enter_irqson() before calling the notifiers). Sure i will update in v2. > >> Remove this change since RCU will not be idle during CPU PM notifications >> hence not required to use _rcuidle tracepoint. Using _rcuidle tracepoint >> prevented rpmh driver to be loadable module as these are not exported >> symbols. >> >> This reverts commit efde2659b0fe835732047357b2902cca14f054d9. >> >> Cc: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> >> Cc: John Stultz <john.stultz@linaro.org> >> Cc: Stephen Rothwell <sfr@canb.auug.org.au> >> Signed-off-by: Maulik Shah <mkshah@codeaurora.org> >> --- > Otherwise > > Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Thanks for the review.
Thanks, Maulik
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