| Message ID | 20200615152054.6819-2-ulf.hansson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | cpuidle: psci: Various improvements for PSCI PM domains | expand |
On Mon, Jun 15 2020 at 09:21 -0600, Ulf Hansson wrote: >Currently we allow the cpuidle driver registration to succeed, even if we >failed to enable the OSI mode when the hierarchical DT layout is used. This >means running in a degraded mode, by using the available idle states per >CPU, while also preventing the domain idle states. > >Moving forward, this behaviour looks quite questionable to maintain, as >complexity seems to grow around it, especially when trying to add support >for deferred probe, for example. > >Therefore, let's make the cpuidle driver registration to fail in this >situation, thus relying on the default architectural cpuidle backend for >WFI to be used. > >Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> May be PATCH 3/5 should come before this change, but for this patch itself, please consider - Reviewed-by: Lina Iyer <ilina@codeaurora.org> >--- > drivers/cpuidle/cpuidle-psci-domain.c | 5 ----- > 1 file changed, 5 deletions(-) > >diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c >index 423f03bbeb74..f07786aad673 100644 >--- a/drivers/cpuidle/cpuidle-psci-domain.c >+++ b/drivers/cpuidle/cpuidle-psci-domain.c >@@ -26,7 +26,6 @@ struct psci_pd_provider { > }; > > static LIST_HEAD(psci_pd_providers); >-static bool osi_mode_enabled __initdata; > > static int psci_pd_power_off(struct generic_pm_domain *pd) > { >@@ -272,7 +271,6 @@ static int __init psci_idle_init_domains(void) > goto remove_pd; > } > >- osi_mode_enabled = true; > of_node_put(np); > pr_info("Initialized CPU PM domain topology\n"); > return pd_count; >@@ -293,9 +291,6 @@ struct device __init *psci_dt_attach_cpu(int cpu) > { > struct device *dev; > >- if (!osi_mode_enabled) >- return NULL; >- > dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci"); > if (IS_ERR_OR_NULL(dev)) > return dev; >-- >2.20.1 >
On Mon, Jun 15, 2020 at 05:20:50PM +0200, Ulf Hansson wrote: > Currently we allow the cpuidle driver registration to succeed, even if we > failed to enable the OSI mode when the hierarchical DT layout is used. This > means running in a degraded mode, by using the available idle states per > CPU, while also preventing the domain idle states. > Is that not better than not registering itself ? I tend to disagree here. > Moving forward, this behaviour looks quite questionable to maintain, as > complexity seems to grow around it, especially when trying to add support > for deferred probe, for example. > I thought the sync_state in the driver must deal with that. > Therefore, let's make the cpuidle driver registration to fail in this > situation, thus relying on the default architectural cpuidle backend for > WFI to be used. > CPU level states work w/o the need of OSI, and better than WFI. That was the original aim. If that is not working, we must make it work instead of falling back on WFI IMO. -- Regards, Sudeep
On Fri, Jun 26, 2020 at 03:33:55PM +0100, Sudeep Holla wrote: > On Mon, Jun 15, 2020 at 05:20:50PM +0200, Ulf Hansson wrote: > > Currently we allow the cpuidle driver registration to succeed, even if we > > failed to enable the OSI mode when the hierarchical DT layout is used. This > > means running in a degraded mode, by using the available idle states per > > CPU, while also preventing the domain idle states. > > > > Is that not better than not registering itself ? I tend to disagree here. > > > Moving forward, this behaviour looks quite questionable to maintain, as > > complexity seems to grow around it, especially when trying to add support > > for deferred probe, for example. > > > > I thought the sync_state in the driver must deal with that. > Ignore this I got confused and assumed we have this in the code while I read 5/5 first 🙁 -- Regards, Sudeep
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c index 423f03bbeb74..f07786aad673 100644 --- a/drivers/cpuidle/cpuidle-psci-domain.c +++ b/drivers/cpuidle/cpuidle-psci-domain.c @@ -26,7 +26,6 @@ struct psci_pd_provider { }; static LIST_HEAD(psci_pd_providers); -static bool osi_mode_enabled __initdata; static int psci_pd_power_off(struct generic_pm_domain *pd) { @@ -272,7 +271,6 @@ static int __init psci_idle_init_domains(void) goto remove_pd; } - osi_mode_enabled = true; of_node_put(np); pr_info("Initialized CPU PM domain topology\n"); return pd_count; @@ -293,9 +291,6 @@ struct device __init *psci_dt_attach_cpu(int cpu) { struct device *dev; - if (!osi_mode_enabled) - return NULL; - dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci"); if (IS_ERR_OR_NULL(dev)) return dev;
Currently we allow the cpuidle driver registration to succeed, even if we failed to enable the OSI mode when the hierarchical DT layout is used. This means running in a degraded mode, by using the available idle states per CPU, while also preventing the domain idle states. Moving forward, this behaviour looks quite questionable to maintain, as complexity seems to grow around it, especially when trying to add support for deferred probe, for example. Therefore, let's make the cpuidle driver registration to fail in this situation, thus relying on the default architectural cpuidle backend for WFI to be used. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- drivers/cpuidle/cpuidle-psci-domain.c | 5 ----- 1 file changed, 5 deletions(-) -- 2.20.1