From: Shawn Guo <shawn.guo@linaro.org>
Date: Sat, 4 Mar 2023 15:41:07 +0800
Subject: [PATCH] cpuidle: psci: Iterate backwards over list in
psci_pd_remove()
References: bsc#1012628
Patch-mainline: 6.2.8
Git-commit: 6b0313c2fa3d2cf991c9ffef6fae6e7ef592ce6d
commit 6b0313c2fa3d2cf991c9ffef6fae6e7ef592ce6d upstream.
In case that psci_pd_init_topology() fails for some reason,
psci_pd_remove() will be responsible for deleting provider and removing
genpd from psci_pd_providers list. There will be a failure when removing
the cluster PD, because the cpu (child) PDs haven't been removed.
[ 0.050232] CPUidle PSCI: init PM domain cpu0
[ 0.050278] CPUidle PSCI: init PM domain cpu1
[ 0.050329] CPUidle PSCI: init PM domain cpu2
[ 0.050370] CPUidle PSCI: init PM domain cpu3
[ 0.050422] CPUidle PSCI: init PM domain cpu-cluster0
[ 0.050475] PM: genpd_remove: unable to remove cpu-cluster0
[ 0.051412] PM: genpd_remove: removed cpu3
[ 0.051449] PM: genpd_remove: removed cpu2
[ 0.051499] PM: genpd_remove: removed cpu1
[ 0.051546] PM: genpd_remove: removed cpu0
Fix the problem by iterating the provider list reversely, so that parent
PD gets removed after child's PDs like below.
[ 0.029052] CPUidle PSCI: init PM domain cpu0
[ 0.029076] CPUidle PSCI: init PM domain cpu1
[ 0.029103] CPUidle PSCI: init PM domain cpu2
[ 0.029124] CPUidle PSCI: init PM domain cpu3
[ 0.029151] CPUidle PSCI: init PM domain cpu-cluster0
[ 0.029647] PM: genpd_remove: removed cpu0
[ 0.029666] PM: genpd_remove: removed cpu1
[ 0.029690] PM: genpd_remove: removed cpu2
[ 0.029714] PM: genpd_remove: removed cpu3
[ 0.029738] PM: genpd_remove: removed cpu-cluster0
Fixes: a65a397f2451 ("cpuidle: psci: Add support for PM domains by using genpd")
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/cpuidle/cpuidle-psci-domain.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
index c80cf9dd..1fca250d 100644
--- a/drivers/cpuidle/cpuidle-psci-domain.c
+++ b/drivers/cpuidle/cpuidle-psci-domain.c
@@ -103,7 +103,8 @@ static void psci_pd_remove(void)
struct psci_pd_provider *pd_provider, *it;
struct generic_pm_domain *genpd;
- list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
+ list_for_each_entry_safe_reverse(pd_provider, it,
+ &psci_pd_providers, link) {
of_genpd_del_provider(pd_provider->node);
genpd = of_genpd_remove_last(pd_provider->node);
--
2.35.3