Re: [PATCH 1/2] Revert "drivers: qcom: rpmh-rsc: Use rcuidle tracepoints for rpmh"

From: Sai Prakash Ranjan
Date: Thu Aug 20 2020 - 02:19:18 EST


On 2020-08-19 15:37, Maulik Shah wrote:
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().

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.

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@xxxxxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Maulik Shah <mkshah@xxxxxxxxxxxxxx>
---

Reviewed-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>

Thanks,
Sai

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