* [PATCH] cpuidle: psci: Iterate backwards over list in psci_pd_remove()
@ 2022-02-25 8:24 Shawn Guo
2022-02-25 8:30 ` Shawn Guo
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Shawn Guo @ 2022-02-25 8:24 UTC (permalink / raw)
To: Daniel Lezcano, Rafael J . Wysocki
Cc: Sudeep Holla, Ulf Hansson, linux-pm, linux-arm-kernel,
linux-kernel, Shawn Guo
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 in a reversely order, so
that parent PD gets removed before child's PDs.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
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 ff2c3f8e4668..ce5c415fb04d 100644
--- a/drivers/cpuidle/cpuidle-psci-domain.c
+++ b/drivers/cpuidle/cpuidle-psci-domain.c
@@ -182,7 +182,8 @@ 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);
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] cpuidle: psci: Iterate backwards over list in psci_pd_remove()
2022-02-25 8:24 [PATCH] cpuidle: psci: Iterate backwards over list in psci_pd_remove() Shawn Guo
@ 2022-02-25 8:30 ` Shawn Guo
2022-02-25 14:14 ` Sudeep Holla
2022-03-01 10:46 ` Ulf Hansson
2 siblings, 0 replies; 4+ messages in thread
From: Shawn Guo @ 2022-02-25 8:30 UTC (permalink / raw)
To: Daniel Lezcano, Rafael J . Wysocki
Cc: Sudeep Holla, Ulf Hansson, linux-pm, linux-arm-kernel,
linux-kernel
On Fri, Feb 25, 2022 at 04:24:20PM +0800, Shawn Guo wrote:
> 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 in a reversely order, so
s/reversely/reversed
> that parent PD gets removed before child's PDs.
s/before/after
Essentially, with this change, the PM domains will be removed in the same
order how they were added.
[ 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
Shawn
>
> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> ---
> 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 ff2c3f8e4668..ce5c415fb04d 100644
> --- a/drivers/cpuidle/cpuidle-psci-domain.c
> +++ b/drivers/cpuidle/cpuidle-psci-domain.c
> @@ -182,7 +182,8 @@ 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);
> --
> 2.25.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] cpuidle: psci: Iterate backwards over list in psci_pd_remove()
2022-02-25 8:24 [PATCH] cpuidle: psci: Iterate backwards over list in psci_pd_remove() Shawn Guo
2022-02-25 8:30 ` Shawn Guo
@ 2022-02-25 14:14 ` Sudeep Holla
2022-03-01 10:46 ` Ulf Hansson
2 siblings, 0 replies; 4+ messages in thread
From: Sudeep Holla @ 2022-02-25 14:14 UTC (permalink / raw)
To: Shawn Guo
Cc: Daniel Lezcano, Rafael J . Wysocki, Sudeep Holla, Ulf Hansson,
linux-pm, linux-arm-kernel, linux-kernel
On Fri, Feb 25, 2022 at 04:24:20PM +0800, Shawn Guo wrote:
> 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 in a reversely order, so
> that parent PD gets removed before child's PDs.
>
Makes sense.
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] cpuidle: psci: Iterate backwards over list in psci_pd_remove()
2022-02-25 8:24 [PATCH] cpuidle: psci: Iterate backwards over list in psci_pd_remove() Shawn Guo
2022-02-25 8:30 ` Shawn Guo
2022-02-25 14:14 ` Sudeep Holla
@ 2022-03-01 10:46 ` Ulf Hansson
2 siblings, 0 replies; 4+ messages in thread
From: Ulf Hansson @ 2022-03-01 10:46 UTC (permalink / raw)
To: Shawn Guo
Cc: Daniel Lezcano, Rafael J . Wysocki, Sudeep Holla, linux-pm,
linux-arm-kernel, linux-kernel
On Fri, 25 Feb 2022 at 09:24, Shawn Guo <shawn.guo@linaro.org> wrote:
>
> 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 in a reversely order, so
> that parent PD gets removed before child's PDs.
>
> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Thanks for fixing this!
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
I think we should add a fixes tag, like below and also tag this for
stable kernels.
Fixes: a65a397f2451 ("cpuidle: psci: Add support for PM domains by using genpd")
Kind regards
Uffe
> ---
> 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 ff2c3f8e4668..ce5c415fb04d 100644
> --- a/drivers/cpuidle/cpuidle-psci-domain.c
> +++ b/drivers/cpuidle/cpuidle-psci-domain.c
> @@ -182,7 +182,8 @@ 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);
> --
> 2.25.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-02-25 8:24 [PATCH] cpuidle: psci: Iterate backwards over list in psci_pd_remove() Shawn Guo
2022-02-25 8:30 ` Shawn Guo
2022-02-25 14:14 ` Sudeep Holla
2022-03-01 10:46 ` Ulf Hansson
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