ARM: OMAP2+: powerdomain: use raw_smp_processor_id() for trace

Message ID 1520589020-14018-1-git-send-email-t-kristo@ti.com
State New
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Series
  • ARM: OMAP2+: powerdomain: use raw_smp_processor_id() for trace
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Commit Message

Tero Kristo March 9, 2018, 9:50 a.m.
smp_processor_id() checks preemption if CONFIG_DEBUG_PREEMPT is enabled,
causing a warning dump during boot:

[    5.042377] BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
[    5.050281] caller is pwrdm_set_next_pwrst+0x48/0x88
[    5.055330] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.14.24-g57341df0b4 #1

Use the raw_smp_processor_id() for the trace instead, this value does
not need to be perfectly correct. The alternative of disabling preempt
is too heavy weight operation to be applied in PM hot path for just
tracing purposes.

Signed-off-by: Tero Kristo <t-kristo@ti.com>

---
 arch/arm/mach-omap2/powerdomain.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
1.9.1

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Comments

Tony Lindgren May 1, 2018, 2:50 p.m. | #1
* Tero Kristo <t-kristo@ti.com> [180309 01:51]:
> smp_processor_id() checks preemption if CONFIG_DEBUG_PREEMPT is enabled,

> causing a warning dump during boot:

> 

> [    5.042377] BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1

> [    5.050281] caller is pwrdm_set_next_pwrst+0x48/0x88

> [    5.055330] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.14.24-g57341df0b4 #1

> 

> Use the raw_smp_processor_id() for the trace instead, this value does

> not need to be perfectly correct. The alternative of disabling preempt

> is too heavy weight operation to be applied in PM hot path for just

> tracing purposes.


Sorry just noticed this is still pending while looking through
my inbox. Applying into omap-for-v4.17/fixes.

Regards,

Tony
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Patch

diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index 76eb6ec..1e6a967 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -188,7 +188,7 @@  static int _pwrdm_state_switch(struct powerdomain *pwrdm, int flag)
 				       ((prev & OMAP_POWERSTATE_MASK) << 0));
 			trace_power_domain_target_rcuidle(pwrdm->name,
 							  trace_state,
-							  smp_processor_id());
+							  raw_smp_processor_id());
 		}
 		break;
 	default:
@@ -518,7 +518,7 @@  int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
 	if (arch_pwrdm && arch_pwrdm->pwrdm_set_next_pwrst) {
 		/* Trace the pwrdm desired target state */
 		trace_power_domain_target_rcuidle(pwrdm->name, pwrst,
-						  smp_processor_id());
+						  raw_smp_processor_id());
 		/* Program the pwrdm desired target state */
 		ret = arch_pwrdm->pwrdm_set_next_pwrst(pwrdm, pwrst);
 	}