[PATCH 09/14] PM: domains: Fixup QoS latency measurements for IRQ safe devices in genpd

Ulf Hansson ulf.hansson at linaro.org
Wed May 11 07:56:59 PDT 2022


When an IRQ safe device is attached to a non-IRQ safe PM domain, genpd
needs to prevent the PM domain from being powered off. However, genpd still
allows the device to be runtime suspended/resumed, hence it's also
reasonable to think that a governor may be used to validate the QoS latency
constraints.

Unfortunately, genpd_runtime_resume() treats the configuration above, as a
reason to skip measuring the QoS resume latency for the device. This is a
legacy behaviour that was earlier correct, but should have been changed
when genpd was transformed into its current behaviour around how it manages
IRQ safe devices. Luckily, there's no report about problems, so let's just
fixup the behaviour.

Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
---
 drivers/base/power/domain.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 2cdfbe48dde0..48101232fcb9 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -970,10 +970,8 @@ static int genpd_runtime_resume(struct device *dev)
 	 * As we don't power off a non IRQ safe domain, which holds
 	 * an IRQ safe device, we don't need to restore power to it.
 	 */
-	if (irq_safe_dev_in_sleep_domain(dev, genpd)) {
-		timed = false;
+	if (irq_safe_dev_in_sleep_domain(dev, genpd))
 		goto out;
-	}
 
 	genpd_lock(genpd);
 	ret = genpd_power_on(genpd, 0);
-- 
2.25.1




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