On 04/03/2014 10:03 AM, dongsheng.w...@freescale.com wrote:


-----Original Message-----
From: Daniel Lezcano [mailto:daniel.lezc...@linaro.org]
Sent: Thursday, April 03, 2014 2:29 PM
To: Wang Dongsheng-B40534; Wood Scott-B07421
Cc: r...@rjwysocki.net; Li Yang-Leo-R58472; Jin Zhengxiong-R64188; Zhao Chenhui-
B35336; linux...@vger.kernel.org; linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] cpuidle: add freescale e500 family porcessors idle support

On 04/03/2014 05:20 AM, dongsheng.w...@freescale.com wrote:
Hi Daniel,

Thanks for your review. I will fix your comments.

BTW, fix Rafael's email. :)

+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/notifier.h>
+
+#include <asm/cputable.h>
+#include <asm/machdep.h>
+#include <asm/mpc85xx.h>
+
+static unsigned int max_idle_state; static struct cpuidle_state
+*cpuidle_state_table;
+
+struct cpuidle_driver e500_idle_driver = {
+       .name = "e500_idle",
+       .owner = THIS_MODULE,
+};
+
+static void e500_cpuidle(void)
+{
+       if (cpuidle_idle_call())
+               cpuidle_wait();
+}

Nope, that has been changed. No more call to cpuidle_idle_call in a driver.


Thanks.

+
+static int pw10_enter(struct cpuidle_device *dev,
+                       struct cpuidle_driver *drv, int index) {
+       cpuidle_wait();
+       return index;
+}
+
+#define MAX_BIT        63
+#define MIN_BIT        1
+extern u32 cpuidle_entry_bit;
+static int pw20_enter(struct cpuidle_device *dev,
+               struct cpuidle_driver *drv, int index) {
+       u32 pw20_idle;
+       u32 entry_bit;
+       pw20_idle = mfspr(SPRN_PWRMGTCR0);
+       if ((pw20_idle & PWRMGTCR0_PW20_ENT) != PWRMGTCR0_PW20_ENT) {
+               pw20_idle &= ~PWRMGTCR0_PW20_ENT;
+               entry_bit = MAX_BIT - cpuidle_entry_bit;
+               pw20_idle |= (entry_bit << PWRMGTCR0_PW20_ENT_SHIFT);
+               mtspr(SPRN_PWRMGTCR0, pw20_idle);
+       }
+
+       cpuidle_wait();
+
+       pw20_idle &= ~PWRMGTCR0_PW20_ENT;
+       pw20_idle |= (MIN_BIT << PWRMGTCR0_PW20_ENT_SHIFT);
+       mtspr(SPRN_PWRMGTCR0, pw20_idle);
+
+       return index;
+}

Is it possible to give some comments and encapsulate the code with
explicit function names to be implemented in an arch specific
directory file (eg. pm.c) and export these functions in a linux/
header ? We try to prevent to include asm if possible.


Yep, Looks better. Thanks.

+
+static struct cpuidle_state pw_idle_states[] = {
+       {
+               .name = "pw10",
+               .desc = "pw10",
+               .flags = CPUIDLE_FLAG_TIME_VALID,
+               .exit_latency = 0,
+               .target_residency = 0,
+               .enter = &pw10_enter
+       },
+
+       {
+               .name = "pw20",
+               .desc = "pw20-core-idle",
+               .flags = CPUIDLE_FLAG_TIME_VALID,
+               .exit_latency = 1,
+               .target_residency = 50,
+               .enter = &pw20_enter
+       },
+};

No need to define this intermediate structure here, you can directly
initialize the cpuidle_driver:


Thanks. :)

+static int cpu_hotplug_notify(struct notifier_block *n,
+                       unsigned long action, void *hcpu) {
+       unsigned long hotcpu = (unsigned long)hcpu;
+       struct cpuidle_device *dev =
+                       per_cpu_ptr(cpuidle_devices, hotcpu);
+
+       if (dev && cpuidle_get_driver()) {
+               switch (action) {
+               case CPU_ONLINE:
+               case CPU_ONLINE_FROZEN:
+                       cpuidle_pause_and_lock();
+                       cpuidle_enable_device(dev);
+                       cpuidle_resume_and_unlock();
+                       break;
+
+               case CPU_DEAD:
+               case CPU_DEAD_FROZEN:
+                       cpuidle_pause_and_lock();
+                       cpuidle_disable_device(dev);
+                       cpuidle_resume_and_unlock();
+                       break;
+
+               default:
+                       return NOTIFY_DONE;
+               }
+       }
+
+       return NOTIFY_OK;
+}
+
+static struct notifier_block cpu_hotplug_notifier = {
+       .notifier_call = cpu_hotplug_notify, };

Can you explain why this is needed ?


If a cpu will be plugged out/in, We should be let Cpuidle know to
remove corresponding sys interface and disable/enable cpudile-governor for
current cpu.

Ok, this code is a copy-paste of the powers' cpuidle driver.

IIRC, I posted a patchset to move this portion of code in the cpuidle common
framework some time ago.

Could you please get rid of this part of code ?


Yes, I can. :) Could you share me your patchset link? I can't found them on 
your tree.


It was a while ago. I should have it somewhere locally. I will find it out and resend the patch next week when finishing my current task.

  -- Daniel

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Blog





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 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

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