From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: rjw@rjwysocki.net
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org,
lina.iyer@linaro.org, Lorenzo.Pieralisi@arm.com
Subject: [PATCH 7/8] ARM: cpuidle: Register per cpuidle device
Date: Wed, 25 Mar 2015 10:07:15 +0100 [thread overview]
Message-ID: <1427274436-21916-7-git-send-email-daniel.lezcano@linaro.org> (raw)
In-Reply-To: <1427274436-21916-1-git-send-email-daniel.lezcano@linaro.org>
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
WARNING: multiple messages have this Message-ID (diff)
From: daniel.lezcano@linaro.org (Daniel Lezcano)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 7/8] ARM: cpuidle: Register per cpuidle device
Date: Wed, 25 Mar 2015 10:07:15 +0100 [thread overview]
Message-ID: <1427274436-21916-7-git-send-email-daniel.lezcano@linaro.org> (raw)
In-Reply-To: <1427274436-21916-1-git-send-email-daniel.lezcano@linaro.org>
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
next prev parent reply other threads:[~2015-03-25 9:08 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-25 9:05 [GIT PULL] : ARM cpuidle changes for 4.1 Daniel Lezcano
2015-03-25 9:05 ` Daniel Lezcano
2015-03-25 9:07 ` [PATCH 1/8] ARM: cpuidle: Remove duplicate header inclusion Daniel Lezcano
2015-03-25 9:07 ` Daniel Lezcano
2015-03-25 9:07 ` [PATCH 2/8] ARM: cpuidle: Add a cpuidle ops structure to be used for DT Daniel Lezcano
2015-03-25 9:07 ` Daniel Lezcano
2015-03-25 9:07 ` Daniel Lezcano
2015-03-25 9:07 ` [PATCH 3/8] ARM64: cpuidle: Replace cpu_suspend by the common ARM/ARM64 function Daniel Lezcano
2015-03-25 9:07 ` Daniel Lezcano
2015-03-25 9:07 ` [PATCH 4/8] ARM64: cpuidle: Rename cpu_init_idle to a common function name Daniel Lezcano
2015-03-25 9:07 ` Daniel Lezcano
2015-03-25 9:07 ` [PATCH 5/8] ARM64: cpuidle: Remove arm64 reference Daniel Lezcano
2015-03-25 9:07 ` Daniel Lezcano
2015-03-25 9:07 ` [PATCH 6/8] ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64 Daniel Lezcano
2015-03-25 9:07 ` Daniel Lezcano
2015-03-25 20:54 ` Paul Bolle
2015-03-25 20:54 ` Paul Bolle
2015-03-25 22:02 ` Daniel Lezcano
2015-03-25 22:02 ` Daniel Lezcano
2015-03-25 9:07 ` Daniel Lezcano [this message]
2015-03-25 9:07 ` [PATCH 7/8] ARM: cpuidle: Register per cpuidle device Daniel Lezcano
2015-03-25 9:07 ` [PATCH 8/8] ARM: cpuidle: Document the code Daniel Lezcano
2015-03-25 9:07 ` Daniel Lezcano
2015-03-25 11:47 ` [GIT PULL] : ARM cpuidle changes for 4.1 Rafael J. Wysocki
2015-03-25 11:47 ` Rafael J. Wysocki
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