On Wed, 19 Aug 2020 at 12:08, Maulik Shah <mkshah@xxxxxxxxxxxxxx> 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> Along with Stephen's comments, feel free to add: Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Also note, when using the PSCI OSI mode, I am proposing to use "genpd on/off notifiers" [1]. This may lead to similar RCU issues, but let's come back to adress that later on, when/if needed. Kind regards Uffe [1] https://www.spinics.net/lists/kernel/msg3629443.html > --- > drivers/soc/qcom/rpmh-rsc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c > index ae66757..fabe390d 100644 > --- a/drivers/soc/qcom/rpmh-rsc.c > +++ b/drivers/soc/qcom/rpmh-rsc.c > @@ -495,7 +495,7 @@ static void __tcs_buffer_write(struct rsc_drv *drv, int tcs_id, int cmd_id, > write_tcs_cmd(drv, RSC_DRV_CMD_MSGID, tcs_id, j, msgid); > write_tcs_cmd(drv, RSC_DRV_CMD_ADDR, tcs_id, j, cmd->addr); > write_tcs_cmd(drv, RSC_DRV_CMD_DATA, tcs_id, j, cmd->data); > - trace_rpmh_send_msg_rcuidle(drv, tcs_id, j, msgid, cmd); > + trace_rpmh_send_msg(drv, tcs_id, j, msgid, cmd); > } > > write_tcs_reg(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id, cmd_complete); > -- > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member > of Code Aurora Forum, hosted by The Linux Foundation >
