Re: [RFC PATCH v15 02/11] ARM: qcom: Add Subsystem Power Manager (SPM) driver

[Lina Iyer <lina.iyer@linaro.org>]

On Mon, Mar 16 2015 at 15:51 -0600, Stephen Boyd wrote:
>On 03/09/15 08:16, Lina Iyer wrote:
>> +
>> +static int qcom_idle_enter(int cpu, unsigned long index)
>> +{
>> +	if (!per_cpu(qcom_idle_ops, cpu)[index])
>> +		return -EOPNOTSUPP;
>
>Is this case still happening?
>
I think, I can remove it safely now.
>> +
>> +	return per_cpu(qcom_idle_ops, cpu)[index](cpu);
>> +}
>> +
>> +const struct of_device_id qcom_idle_state_match[] __initconst = {
>
>static?
>
Ok

>> +	{ .compatible = "qcom,idle-state-stby", .data = qcom_cpu_standby },
>> +	{ .compatible = "qcom,idle-state-spc", .data = qcom_cpu_spc },
>> +	{ },
>> +};
>> +
>> +static int __init qcom_cpuidle_init(struct device_node *cpu_node, int cpu)
>> +{
>> +	const struct of_device_id *match_id;
>> +	struct device_node *state_node;
>> +	int i;
>> +	int state_count = 0;
>> +	idle_fn idle_fns[CPUIDLE_STATE_MAX];
>> +	idle_fn *fns;
>> +	cpumask_t mask;
>> +	bool use_scm_power_down = false;
>> +
>> +	for (i = 0; ; i++) {
>> +		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
>> +		if (!state_node)
>> +			break;
>> +
>> +		if (!of_device_is_available(state_node))
>> +			continue;
>> +
>> +		if (i == CPUIDLE_STATE_MAX) {
>> +			pr_warn("%s: cpuidle states reached max possible\n",
>> +					__func__);
>> +			break;
>> +		}
>> +
>> +		match_id = of_match_node(qcom_idle_state_match, state_node);
>> +		if (!match_id)
>> +			return -ENODEV;
>> +
>> +		idle_fns[state_count] = match_id->data;
>> +
>> +		/* Check if any of the states allow power down */
>> +		if (match_id->data == qcom_cpu_spc)
>> +			use_scm_power_down = true;
>> +
>> +		state_count++;
>> +	}
>> +
>> +	if (!state_count) {
>> +		pr_warn("No idle ops founds for cpu %d\n", cpu);
>
>Maybe pr_debug? It's not the end of the world that we don't have cpuidle.
>
Sure.

>> +		return -ENODEV;
>> +	}
>> +
>> +	fns = kcalloc(state_count, sizeof(*fns), GFP_KERNEL);
>> +	if (!fns)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < state_count; i++)
>> +		fns[i] = idle_fns[i];
>> +
>> +	if (use_scm_power_down) {
>> +		/* We have atlease one power down mode */
>
>s/atlease/at least/
>
Thanks!

>> +		cpumask_clear(&mask);
>> +		cpumask_set_cpu(cpu, &mask);
>> +		qcom_scm_set_warm_boot_addr(cpu_resume, &mask);
>> +	}
>> +
>> +	per_cpu(qcom_idle_ops, cpu) = fns;
>> +
>> +	/*
>> +	 * Condition: cpuidle_driver_register() needs to happen before
>> +	 * cpuidle_register_device().
>> +	 * Check if the SPM probe has happened -
>> +	 * - If SPM probed successfully before arm_idle_init(), then defer
>> +	 *   the registration of cpuidle_device back to arm_idle_init()
>> +	 * - If the SPM probe happens in the future, then let the SPM probe
>> +	 *   register the cpuidle device, return -ENOSYS.
>> +	 */
>> +	return per_cpu(cpu_spm_drv, cpu) ? 0 : -ENOSYS;
>> +}
>> +
>> +struct cpuidle_ops qcom_kpss_v1_cpuidle_ops __initdata = {
>> +	.name = "qcom,kpss-acc-v1",
>> +	.suspend = qcom_idle_enter,
>> +	.init = qcom_cpuidle_init,
>> +};
>> +
>> +struct cpuidle_ops qcom_kpss_v2_cpuidle_ops __initdata = {
>> +	.name = "qcom,kpss-acc-v2",
>> +	.suspend = qcom_idle_enter,
>> +	.init = qcom_cpuidle_init,
>> +};
>> +
>>
>
>This just looks weird because of the macro magic in Daniel's series. Any
>reason we can't use the linker instead of doing preprocessor magic so
>that it looks like these structures are actually used?
>
Hmm.. Will wait on Daniel's response to your other mail.

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>