Hi Nicolas,
On Sat, Jul 5, 2014 at 12:00 AM, Nicolas Pitre <nicolas.pitre@xxxxxxxxxx> wrote:
> On Fri, 4 Jul 2014, Abhilash Kesavan wrote:
>
>> On Fri, Jul 4, 2014 at 9:43 AM, Nicolas Pitre <nicolas.pitre@xxxxxxxxxx> wrote:
>> > Another suggestion which might possibly be better: why not looking for
>> > the SYS_PWR_CFG bit in exynos_cpu_power_down() directly? After all,
>> > exynos_cpu_power_down() is semantically supposed to do what its name
>> > suggest and could simply do nothing if the proper conditions are already
>> > in place.
>> I have implemented this and it works fine. Patch coming up.
>
> On Fri, 4 Jul 2014, Abhilash Kesavan wrote:
>
>> Use the MCPM layer to handle core suspend/resume on Exynos5420.
>> Also, restore the entry address setup code post-resume.
>>
>> Signed-off-by: Abhilash Kesavan <a.kesavan@xxxxxxxxxxx>
>> ---
>> Changes in v2:
>> - Made use of the MCPM suspend/powered_up call-backs
>> Changes in v3:
>> - Used the residency value to indicate the entered state
>> Changes in v4:
>> - Checked if MCPM has been enabled to prevent build error
>> Changes in v5:
>> - Removed the MCPM flags and just used a local flag to
>> indicate that we are suspending.
>> Changes in v6:
>> - Read the SYS_PWR_REG value to decide if we are suspending
>> the system.
>> - Restore the SYS_PWR_REG value post-resume.
>> - Modified the comments to reflect the first change.
>
> [...]
>
>> @@ -150,7 +153,15 @@ static void exynos_power_down(void)
>> BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
>> cpu_use_count[cpu][cluster]--;
>> if (cpu_use_count[cpu][cluster] == 0) {
>> - exynos_cpu_power_down(cpunr);
>> + /*
>> + * Bypass power down for CPU0 during suspend. Check for
>> + * the SYS_PWR_REG value to decide if we are suspending
>> + * the system.
>> + */
>> + temp = __raw_readl(pmu_base_addr +
>> + EXYNOS5_ARM_CORE0_SYS_PWR_REG);
>> + if ((cpu != 0) || ((temp & S5P_CORE_LOCAL_PWR_EN) != 0))
>> + exynos_cpu_power_down(cpunr);
>
> Nah... We're going in circles, aren't we?
>
> What I suggested above is:
>
> diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
> index 67d383de61..0a48421860 100644
> --- a/arch/arm/mach-exynos/pm.c
> +++ b/arch/arm/mach-exynos/pm.c
> @@ -110,6 +110,16 @@ static int exynos_irq_set_wake(struct irq_data *data, unsigned int state)
> */
> void exynos_cpu_power_down(int cpu)
> {
> + if (soc_is_exynos5250() && cpu == 0) {
> + /*
> + * Bypass power down for CPU0 during suspend. Check for
> + * the SYS_PWR_REG value to decide if we are suspending
> + * the system.
> + */
> + int val = __raw_readl(pmu_base_addr +EXYNOS5_ARM_CORE0_SYS_PWR_REG);
> + if (!(val & S5P_CORE_LOCAL_PWR_EN))
> + return;
> + }
> __raw_writel(0, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
> }
Ah, I get it, much nicer indeed. Will change.
>
>
> Nicolas
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