[PATCH] firmware/psci: Move psci_init_system_suspend() to late_initcall()

[Maulik Shah]

psci_init_system_suspend() invokes suspend_set_ops() very early during
bootup even before kernel command line for mem_sleep_default is setup.
This leads to kernel command line mem_sleep_default=s2idle not working
as mem_sleep_current gets changed to deep via suspend_set_ops() and never
changes back to s2idle.

Move psci_init_system_suspend() to late_initcall() to make sure kernel
command line mem_sleep_default=s2idle sets up s2idle as default suspend
mode.

Fixes: faf7ec4a92c0 ("drivers: firmware: psci: add system suspend support")
CC: stable@xxxxxxxxxxxxxxx # 5.15+
Signed-off-by: Maulik Shah <quic_mkshah@xxxxxxxxxxx>
---
 drivers/firmware/psci/psci.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index d9629ff87861..655a2db70a67 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -523,18 +523,26 @@ static void __init psci_init_system_reset2(void)
 		psci_system_reset2_supported = true;
 }
 
-static void __init psci_init_system_suspend(void)
+static int __init psci_init_system_suspend(void)
 {
 	int ret;
+	u32 ver;
 
 	if (!IS_ENABLED(CONFIG_SUSPEND))
-		return;
+		return 0;
+
+	ver = psci_0_2_get_version();
+	if (PSCI_VERSION_MAJOR(ver) < 1)
+		return 0;
 
 	ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
 
 	if (ret != PSCI_RET_NOT_SUPPORTED)
 		suspend_set_ops(&psci_suspend_ops);
+
+	return ret;
 }
+late_initcall(psci_init_system_suspend)
 
 static void __init psci_init_cpu_suspend(void)
 {
@@ -651,7 +659,6 @@ static int __init psci_probe(void)
 	if (PSCI_VERSION_MAJOR(ver) >= 1) {
 		psci_init_smccc();
 		psci_init_cpu_suspend();
-		psci_init_system_suspend();
 		psci_init_system_reset2();
 		kvm_init_hyp_services();
 	}

---
base-commit: d37e1e4c52bc60578969f391fb81f947c3e83118
change-id: 20240219-suspend_ops_late_init-27fb0b15baee

Best regards,
-- 
Maulik Shah <quic_mkshah@xxxxxxxxxxx>