[PATCH AUTOSEL 5.6 140/149] drivers: qcom: rpmh-rsc: Use rcuidle tracepoints for rpmh

Sasha Levin
2020-04-11T23:06:54Z

From: Stephen Boyd <swboyd@chromium.org>

[ Upstream commit efde2659b0fe835732047357b2902cca14f054d9 ]

This tracepoint is hit now that we call into the rpmh code from the cpu
idle path. Let's move this to be an rcuidle tracepoint so that we avoid
the RCU idle splat below

=============================
WARNING: suspicious RCU usage
5.4.10 #68 Tainted: G S
-----------------------------
drivers/soc/qcom/trace-rpmh.h:72 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

RCU used illegally from idle CPU!
rcu_scheduler_active = 2, debug_locks = 1
RCU used illegally from extended quiescent state!
5 locks held by swapper/2/0:
#0: ffffff81745d6ee8 (&(&genpd->slock)->rlock){+.+.}, at: genpd_lock_spin+0x1c/0x2c
#1: ffffff81745da6e8 (&(&genpd->slock)->rlock/1){....}, at: genpd_lock_nested_spin+0x24/0x34
#2: ffffff8174f2ca20 (&(&genpd->slock)->rlock/2){....}, at: genpd_lock_nested_spin+0x24/0x34
#3: ffffff8174f2c300 (&(&drv->client.cache_lock)->rlock){....}, at: rpmh_flush+0x48/0x24c
#4: ffffff8174f2c150 (&(&tcs->lock)->rlock){+.+.}, at: rpmh_rsc_write_ctrl_data+0x74/0x270

stack backtrace:
CPU: 2 PID: 0 Comm: swapper/2 Tainted: G S 5.4.10 #68
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
genpd_power_off+0x1e0/0x208
genpd_power_off+0x1e0/0x208
genpd_runtime_suspend+0x1ac/0x220
__rpm_callback+0x70/0xfc
rpm_callback+0x34/0x8c
rpm_suspend+0x218/0x4a4
__pm_runtime_suspend+0x88/0xac
psci_enter_domain_idle_state+0x3c/0xb4
cpuidle_enter_state+0xb8/0x284
cpuidle_enter+0x38/0x4c
call_cpuidle+0x3c/0x68
do_idle+0x194/0x260
cpu_startup_entry+0x24/0x28
secondary_start_kernel+0x150/0x15c

Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Fixes: a65a397f2451 ("cpuidle: psci: Add support for PM domains by using genpd")
Reported-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200115013751.249588-1-swboyd@chromium.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 e278fc11fe5cf..b71822131f598 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -277,7 +277,7 @@ 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(drv, tcs_id, j, msgid, cmd);
+ trace_rpmh_send_msg_rcuidle(drv, tcs_id, j, msgid, cmd);
}

write_tcs_reg(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id, cmd_complete);
--
2.20.1