On 07/19/2013 06:03 PM, Bartlomiej Zolnierkiewicz wrote:

Hi,

On Thursday, July 18, 2013 02:54:28 PM Daniel Lezcano wrote:

...

Now we have the same routine than the one handled by the cpuidle framework.

Small nitpick:

To be exact the routine is not the same, on error cpuidle_register() does complete unregister operation of the cpuidle driver, exynos4_init_cpuidle() just stops the registration procedure.

The change itself is okay but the patch description could be better.

Ok, I will fix the changelog.

Anyway all patches (#1-4) look fine to me. Thanks for this work.

Thanks for the review. I assume it is an acked-by right ?

Best regards,

Kukjin,

shall I take the patchset in my tree ?

Thanks -- Daniel

-- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics

...

Let's use it.

Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org

arch/arm/mach-exynos/cpuidle.c | 24 +----------------------- 1 file changed, 1 insertion(+), 23 deletions(-)

diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c index cc4b097..d8fc1a2 100644 --- a/arch/arm/mach-exynos/cpuidle.c +++ b/arch/arm/mach-exynos/cpuidle.c @@ -41,8 +41,6 @@ static int exynos4_enter_lowpower(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); -static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);

static struct cpuidle_driver exynos4_idle_driver = { .name = "exynos4_idle", .owner = THIS_MODULE, @@ -188,29 +186,9 @@ static void __init exynos5_core_down_clk(void) static int __init exynos4_init_cpuidle(void) {

• int cpu_id, ret;
• struct cpuidle_device *device;
• if (soc_is_exynos5250()) exynos5_core_down_clk();

• ret = cpuidle_register_driver(&exynos4_idle_driver);
• if (ret) {

• printk(KERN_ERR "CPUidle failed to register driver\n");
  

• return ret;
  

• }
• for_each_online_cpu(cpu_id) {

• device = &per_cpu(exynos4_cpuidle_device, cpu_id);
  

• device->cpu = cpu_id;
  

• ret = cpuidle_register_device(device);
  

• if (ret) {
  

• 	printk(KERN_ERR "CPUidle register device failed\n");
  

• 	return ret;
  

• }
  

• }
• return 0;

• return cpuidle_register(&exynos4_idle_driver, NULL);

} device_initcall(exynos4_init_cpuidle);

On Thursday 18 of July 2013 14:54:28 Daniel Lezcano wrote:

Now we have the same routine than the one handled by the cpuidle framework.

Let's use it.

Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org

arch/arm/mach-exynos/cpuidle.c | 24 +----------------------- 1 file changed, 1 insertion(+), 23 deletions(-)

diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c index cc4b097..d8fc1a2 100644 --- a/arch/arm/mach-exynos/cpuidle.c +++ b/arch/arm/mach-exynos/cpuidle.c @@ -41,8 +41,6 @@ static int exynos4_enter_lowpower(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index);

-static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);

static struct cpuidle_driver exynos4_idle_driver = { .name = "exynos4_idle", .owner = THIS_MODULE, @@ -188,29 +186,9 @@ static void __init exynos5_core_down_clk(void)

static int __init exynos4_init_cpuidle(void) {

• int cpu_id, ret;

• struct cpuidle_device *device;

• if (soc_is_exynos5250()) exynos5_core_down_clk();

• ret = cpuidle_register_driver(&exynos4_idle_driver);

• if (ret) {

• printk(KERN_ERR "CPUidle failed to register driver\n");
  

• return ret;
  

• }

• for_each_online_cpu(cpu_id) {

• device = &per_cpu(exynos4_cpuidle_device, cpu_id);
  

• device->cpu = cpu_id;
  

• ret = cpuidle_register_device(device);
  

• if (ret) {
  

• 	printk(KERN_ERR "CPUidle register device 
  

failed\n");

• 	return ret;
  

• }
  

• }
• return 0;

• return cpuidle_register(&exynos4_idle_driver, NULL);

} device_initcall(exynos4_init_cpuidle);

This is nice, but I would like to see clarification for my question posted to patch 1/4.

Best regards, Tomasz

On Thursday 18 of July 2013 14:54:29 Daniel Lezcano wrote:

In order to prevent a pointless forward declaration, move the driver declation after the idle function callback, right before the init function.

Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org

arch/arm/mach-exynos/cpuidle.c | 40 ++++++++++++++++++---------------------- 1 file changed, 18 insertions(+), 22 deletions(-)

diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c index d8fc1a2..8d06128 100644 --- a/arch/arm/mach-exynos/cpuidle.c +++ b/arch/arm/mach-exynos/cpuidle.c @@ -37,28 +37,6 @@

#define S5P_CHECK_AFTR 0xFCBA0D10

-static int exynos4_enter_lowpower(struct cpuidle_device *dev,

• 		struct cpuidle_driver *drv,
  

• 		int index);
  

-static struct cpuidle_driver exynos4_idle_driver = {

• .name = "exynos4_idle",
• .owner = THIS_MODULE,
• .states = {

• [0] = ARM_CPUIDLE_WFI_STATE,
  

• [1] = {
  

• 	.enter			= exynos4_enter_lowpower,
  

• 	.exit_latency		= 300,
  

• 	.target_residency	= 100000,
  

• 	.flags			= CPUIDLE_FLAG_TIME_VALID,
  

• 	.name			= "C1",
  

• 	.desc			= "ARM power down",
  

• },
  

• },
• .state_count = 2,
• .safe_state_index = 0,

-};

/* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */ static void exynos4_set_wakeupmask(void) { @@ -184,6 +162,24 @@ static void __init exynos5_core_down_clk(void) __raw_writel(tmp, EXYNOS5_PWR_CTRL2); }

+static struct cpuidle_driver exynos4_idle_driver = {

• .name = "exynos4_idle",
• .owner = THIS_MODULE,
• .states = {

• [0] = ARM_CPUIDLE_WFI_STATE,
  

• [1] = {
  

• 	.enter			= exynos4_enter_lowpower,
  

• 	.exit_latency		= 300,
  

• 	.target_residency	= 100000,
  

• 	.flags			= CPUIDLE_FLAG_TIME_VALID,
  

• 	.name			= "C1",
  

• 	.desc			= "ARM power down",
  

• },
  

• },
• .state_count = 2,
• .safe_state_index = 0,

+};

static int __init exynos4_init_cpuidle(void) { if (soc_is_exynos5250())

Makes sense.

Reviewed-by: Tomasz Figa t.figa@samsung.com

Best regards, Tomasz

On Thursday 18 of July 2013 14:54:30 Daniel Lezcano wrote:

The headers:

#include <linux/kernel.h> #include <linux/export.h> #include <linux/time.h> #include <asm/unified.h>

are not needed. Removed them.

Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org

arch/arm/mach-exynos/cpuidle.c | 4 ---- 1 file changed, 4 deletions(-)

diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c index 8d06128..027f5e7 100644 --- a/arch/arm/mach-exynos/cpuidle.c +++ b/arch/arm/mach-exynos/cpuidle.c @@ -8,18 +8,14 @@

• published by the Free Software Foundation.

*/

-#include <linux/kernel.h> #include <linux/init.h> #include <linux/cpuidle.h> #include <linux/cpu_pm.h> #include <linux/io.h> -#include <linux/export.h> -#include <linux/time.h>

#include <asm/proc-fns.h> #include <asm/smp_scu.h> #include <asm/suspend.h> -#include <asm/unified.h> #include <asm/cpuidle.h> #include <mach/regs-clock.h> #include <mach/regs-pmu.h>

Reviewed-by: Tomasz Figa t.figa@samsung.com

Best regards, Tomasz

On Wednesday, July 24, 2013 10:32:47 AM Tomasz Figa wrote:

Hi Daniel,

On Thursday 18 of July 2013 14:54:27 Daniel Lezcano wrote:

...

When there are several cpus online, the AFTR state does not work.

The AFTR must be selected only when there is one cpu online.

The previous code was already handling this case.

Simplified the code, especially the init routine to have the same init pattern than the other drivers.

Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org

arch/arm/mach-exynos/cpuidle.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c index 17a18ff..cc4b097 100644 --- a/arch/arm/mach-exynos/cpuidle.c +++ b/arch/arm/mach-exynos/cpuidle.c @@ -147,16 +147,11 @@ static int exynos4_enter_lowpower(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) {

• int new_index = index;
• /* This mode only can be entered when other core's are offline */ if (num_online_cpus() > 1)

• new_index = drv->safe_state_index;
  

• return drv->states[0].enter(dev, drv, 0);
  
  

• if (new_index == 0)

• return arm_cpuidle_simple_enter(dev, drv, new_index);
  

• else

• return exynos4_enter_core0_aftr(dev, drv, new_index);
  

• return exynos4_enter_core0_aftr(dev, drv, index);

}

static void __init exynos5_core_down_clk(void) @@ -209,10 +204,6 @@ static int __init exynos4_init_cpuidle(void) device = &per_cpu(exynos4_cpuidle_device, cpu_id); device->cpu = cpu_id;

• /* Support IDLE only */
  

• if (cpu_id != 0)
  

• 	device->state_count = 1;
  

Are you sure that this is okay? It means, assuming that you have CPU0 hotplug enabled, that you can enter the AFTR state if _any_ single core remains plugged in, which is technically possible, but then wake-up will occur on CPU0, which is not what cpuidle and hotplug code expect.

I worry that the current code is already broken in this respect as cpuidle core is using driver->state_count for everything except creating/destroying sysfs state entries. This is probably something that needs to be fixed in the cpuidle core (I suspect that governors should use device->state_count instead of driver->state_count but it would need confirmation from someone that knows this code better) but in the meantime it could be fixed by adding CPU0 check to exynos4_enter_lowpower() (if the last CPU != 0 then don't go into AFTR mode).

Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics

P.S. Please keep linux-samsung-soc@vger.kernel.org mailing list on Cc for patches related to Samsung SoCs.

Best regards, Tomasz