| Message ID | 1427190842-30675-1-git-send-email-daniel.lezcano@linaro.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Tue, Mar 24, 2015 at 09:54:01AM +0000, Daniel Lezcano wrote: > If the cpuidle init cpu operation returns -ENXIO, therefore reporting HW > failure or misconfiguration, the CPUidle driver skips the respective > cpuidle device initialization because the associated platform back-end HW > is not operational. > > That prevents the system to crash and allows to handle the error gracefully. > > For example, on Qcom's platform, each core has a SPM. The device associated > with this SPM is initialized before the cpuidle framework. If there is an error > in the initialization (eg. error in the DT), the system continues to boot but > in degraded mode as some SPM may not be correctly initialized. > > Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > --- > drivers/cpuidle/cpuidle-arm.c | 45 +++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 43 insertions(+), 2 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c > index 1c94b88..545069d 100644 > --- a/drivers/cpuidle/cpuidle-arm.c > +++ b/drivers/cpuidle/cpuidle-arm.c > @@ -17,6 +17,7 @@ > #include <linux/kernel.h> > #include <linux/module.h> > #include <linux/of.h> > +#include <linux/slab.h> > > #include <asm/cpuidle.h> > > @@ -94,6 +95,7 @@ static int __init arm_idle_init(void) > { > int cpu, ret; > struct cpuidle_driver *drv = &arm_idle_driver; > + struct cpuidle_device *dev; > > /* > * Initialize idle states data, starting at index 1. > @@ -105,18 +107,57 @@ static int __init arm_idle_init(void) > if (ret <= 0) > return ret ? : -ENODEV; > > + ret = cpuidle_register_driver(drv); > + if (ret) { > + pr_err("Failed to register cpuidle driver\n"); > + return ret; > + } > + > /* > * Call arch CPU operations in order to initialize > * idle states suspend back-end specific data > */ > for_each_possible_cpu(cpu) { > ret = arm_cpuidle_init(cpu); > + > + /* > + * Skip the cpuidle device initialization if the reported > + * failure is a HW misconfiguration/breakage (-ENXIO). > + */ > + if (ret == -ENXIO) > + continue; > + > if (ret) { > pr_err("CPU %d failed to init idle CPU ops\n", cpu); > - return ret; > + goto out_fail; > + } > + > + dev = kzalloc(sizeof(*dev), GFP_KERNEL); > + if (!dev) { > + pr_err("Failed to allocate cpuidle device\n"); > + goto out_fail; > + } > + dev->cpu = cpu; > + > + ret = cpuidle_register_device(dev); > + if (ret) { > + pr_err("Failed to register cpuidle device for CPU %d\n", > + cpu); > + kfree(dev); > + goto out_fail; > } > } > > - return cpuidle_register(drv, NULL); > + return 0; > +out_fail: > + while (--cpu >= 0) { > + dev = per_cpu(cpuidle_devices, cpu); > + cpuidle_unregister_device(dev); > + kfree(dev); > + } > + > + cpuidle_unregister_driver(drv); > + > + return ret; > } > device_initcall(arm_idle_init); > -- > 1.9.1 > > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c index 1c94b88..545069d 100644 --- a/drivers/cpuidle/cpuidle-arm.c +++ b/drivers/cpuidle/cpuidle-arm.c @@ -17,6 +17,7 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/slab.h> #include <asm/cpuidle.h> @@ -94,6 +95,7 @@ static int __init arm_idle_init(void) { int cpu, ret; struct cpuidle_driver *drv = &arm_idle_driver; + struct cpuidle_device *dev; /* * Initialize idle states data, starting at index 1. @@ -105,18 +107,57 @@ static int __init arm_idle_init(void) if (ret <= 0) return ret ? : -ENODEV; + ret = cpuidle_register_driver(drv); + if (ret) { + pr_err("Failed to register cpuidle driver\n"); + return ret; + } + /* * Call arch CPU operations in order to initialize * idle states suspend back-end specific data */ for_each_possible_cpu(cpu) { ret = arm_cpuidle_init(cpu); + + /* + * Skip the cpuidle device initialization if the reported + * failure is a HW misconfiguration/breakage (-ENXIO). + */ + if (ret == -ENXIO) + continue; + if (ret) { pr_err("CPU %d failed to init idle CPU ops\n", cpu); - return ret; + goto out_fail; + } + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) { + pr_err("Failed to allocate cpuidle device\n"); + goto out_fail; + } + dev->cpu = cpu; + + ret = cpuidle_register_device(dev); + if (ret) { + pr_err("Failed to register cpuidle device for CPU %d\n", + cpu); + kfree(dev); + goto out_fail; } } - return cpuidle_register(drv, NULL); + return 0; +out_fail: + while (--cpu >= 0) { + dev = per_cpu(cpuidle_devices, cpu); + cpuidle_unregister_device(dev); + kfree(dev); + } + + cpuidle_unregister_driver(drv); + + return ret; } device_initcall(arm_idle_init);
If the cpuidle init cpu operation returns -ENXIO, therefore reporting HW failure or misconfiguration, the CPUidle driver skips the respective cpuidle device initialization because the associated platform back-end HW is not operational. That prevents the system to crash and allows to handle the error gracefully. For example, on Qcom's platform, each core has a SPM. The device associated with this SPM is initialized before the cpuidle framework. If there is an error in the initialization (eg. error in the DT), the system continues to boot but in degraded mode as some SPM may not be correctly initialized. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> --- drivers/cpuidle/cpuidle-arm.c | 45 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 43 insertions(+), 2 deletions(-)