diff mbox series

[v2] cpuidle: psci: Iterate backwards over list in psci_pd_remove()

Message ID 20220308082931.3385902-1-shawn.guo@linaro.org (mailing list archive)
State New, archived
Headers show
Series [v2] cpuidle: psci: Iterate backwards over list in psci_pd_remove() | expand

Commit Message

Shawn Guo March 8, 2022, 8:29 a.m. UTC
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>
---
Changes since v1:
- Fix commit log
- Pick up Reviewed-by tag from Sudeep and Ulf (Thanks!)
- Add Fixes tag as suggested by Ulf

 drivers/cpuidle/cpuidle-psci-domain.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Konrad Dybcio March 2, 2023, 2:46 p.m. UTC | #1
On 8.03.2022 09:29, 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 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>
> ---
Looks like this was never picked up or followed up on?

Konrad
> Changes since v1:
> - Fix commit log
> - Pick up Reviewed-by tag from Sudeep and Ulf (Thanks!)
> - Add Fixes tag as suggested by Ulf
> 
>  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);
>
Shawn Guo March 3, 2023, 12:37 a.m. UTC | #2
On Thu, Mar 2, 2023 at 10:46 PM Konrad Dybcio
<konrad.dybcio@somainline.org> wrote:
>
>
>
> On 8.03.2022 09:29, 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 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>
> > ---
> Looks like this was never picked up or followed up on?

Oops!  I thought it was already applied.  I will ping Rafael with a resend.

Shawn
diff mbox series

Patch

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);