[PATCH] pmdomain: arm: scmi_pm_domain: Remove redundant state verification

Sudeep Holla sudeep.holla at arm.com
Fri Mar 14 02:58:51 PDT 2025


Currently, scmi_pd_power() explicitly verifies whether the requested
power state was applied by calling state_get(). While this check could
detect failures where the state was not properly updated, ensuring
correctness is the responsibility of the SCMI firmware.

Removing this redundant state_get() call eliminates an unnecessary
round-trip to the firmware, improving efficiency. Any mismatches
between the requested and actual states should be handled by the SCMI
firmware, which must return a failure if state_set() is unsuccessful.

Additionally, in some cases, checking the state after powering off a
domain may be unreliable or unsafe, depending on the firmware
implementation.

This patch removes the redundant verification, simplifying the function
without compromising correctness.

Cc: Peng Fan <peng.fan at nxp.com>
Cc: Ulf Hansson <ulf.hansson at linaro.org>
Cc: Cristian Marussi <cristian.marussi at arm.com>
Reported-and-tested-by: Ranjani Vaidyanathan <ranjani.vaidyanathan at nxp.com>
Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
---
 drivers/pmdomain/arm/scmi_pm_domain.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/pmdomain/arm/scmi_pm_domain.c b/drivers/pmdomain/arm/scmi_pm_domain.c
index 86b531e15b85..2a213c218126 100644
--- a/drivers/pmdomain/arm/scmi_pm_domain.c
+++ b/drivers/pmdomain/arm/scmi_pm_domain.c
@@ -24,8 +24,7 @@ struct scmi_pm_domain {
 
 static int scmi_pd_power(struct generic_pm_domain *domain, bool power_on)
 {
-	int ret;
-	u32 state, ret_state;
+	u32 state;
 	struct scmi_pm_domain *pd = to_scmi_pd(domain);
 
 	if (power_on)
@@ -33,13 +32,7 @@ static int scmi_pd_power(struct generic_pm_domain *domain, bool power_on)
 	else
 		state = SCMI_POWER_STATE_GENERIC_OFF;
 
-	ret = power_ops->state_set(pd->ph, pd->domain, state);
-	if (!ret)
-		ret = power_ops->state_get(pd->ph, pd->domain, &ret_state);
-	if (!ret && state != ret_state)
-		return -EIO;
-
-	return ret;
+	return power_ops->state_set(pd->ph, pd->domain, state);
 }
 
 static int scmi_pd_power_on(struct generic_pm_domain *domain)
-- 
2.34.1




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