From: lina.iyer@linaro•org (Lina Iyer)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v7 4/7] qcom: pm: Add cpu low power mode functions
Date: Mon, 6 Oct 2014 11:10:32 -0600 [thread overview]
Message-ID: <20141006171032.GA1605@ilina-mac.local> (raw)
In-Reply-To: <20141002095036.GA1938@e102568-lin.cambridge.arm.com>
On Thu, Oct 02 2014 at 03:50 -0600, Lorenzo Pieralisi wrote:
>On Sat, Sep 27, 2014 at 01:58:12AM +0100, Lina Iyer wrote:
>
>[...]
>
>> diff --git a/drivers/soc/qcom/pm.c b/drivers/soc/qcom/pm.c
>> new file mode 100644
>> index 0000000..a2f7d72
>> --- /dev/null
>> +++ b/drivers/soc/qcom/pm.c
>> @@ -0,0 +1,109 @@
>> +static int qcom_pm_collapse(unsigned long int unused)
>> +{
>> + int ret;
>> + u32 flag;
>> +
>> + ret = set_up_boot_address(cpu_resume, raw_smp_processor_id());
>> + if (ret) {
>> + pr_err("Failed to set warm boot address for cpu %d\n",
>> + raw_smp_processor_id());
>> + return ret;
>> + }
>> +
>> + flag = SCM_L2_ON & SCM_FLUSH_FLAG_MASK;
>> + scm_call_atomic1(SCM_SVC_BOOT, SCM_CMD_TERMINATE_PC, flag);
>
>Function call above does not return IIUC (ie it returns through cpu_resume),
>add a comment to clarify please.
>
Sure.
>> +
>> + return 0;
>> +}
>> +
>> +/**
>> + * qcom_cpu_pm_enter_sleep(): Enter a low power mode on current cpu
>> + *
>> + * @mode - sleep mode to enter
>> + *
>> + * The code should be called with interrupts disabled and on the core on
>> + * which the low power mode is to be executed.
>> + *
>> + */
>> +static int qcom_cpu_pm_enter_sleep(enum pm_sleep_mode mode)
>> +{
>> + int ret;
>> +
>> + switch (mode) {
>> + case PM_SLEEP_MODE_SPC:
>> + qcom_spm_set_low_power_mode(SPM_MODE_POWER_COLLAPSE);
>> + ret = cpu_suspend(0, qcom_pm_collapse);
>> + break;
>> + default:
>> + case PM_SLEEP_MODE_WFI:
>> + qcom_spm_set_low_power_mode(SPM_MODE_CLOCK_GATING);
>> + ret = cpu_do_idle();
>
>Hmmm...are we sure the ret value you get from cpu_do_idle() is correct ?
>
>Maybe I am missing something but I do not think that the cpu_do_idle
>implementation (in assembly files mm/proc-* called through cpu_do_idle()
>macro) returns a proper value, it seems to me that it "returns" whatever is
>present in r0 at the time of the call, which might not be what you want.
>
>Am I missing something here ? I do not think you should rely on the
>cpu_do_idle() return value, at least for the moment.
>
Okay. I dont use it beyond this function. I shall remove it from this
function.
>> + break;
>> + }
>> +
>> + local_irq_enable();
>
>This looks wrong to me. You end up running the CPU PM notifiers with irqs
>enabled, among other issues.
>
Good catch. Thanks!
Lina
next prev parent reply other threads:[~2014-10-06 17:10 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-27 0:58 [PATCH v7 0/7] QCOM 8974 and 8084 cpuidle driver Lina Iyer
2014-09-27 0:58 ` [PATCH v7 1/7] qcom: spm: Add Subsystem Power Manager driver Lina Iyer
2014-09-27 8:07 ` Pramod Gurav
2014-09-29 10:29 ` Pramod Gurav
2014-09-29 23:19 ` Stephen Boyd
2014-09-30 16:27 ` Lina Iyer
2014-09-30 17:26 ` Kevin Hilman
2014-09-30 21:18 ` Lina Iyer
2014-09-27 0:58 ` [PATCH v7 2/7] arm: dts: qcom: Add SPM device bindings for 8974 Lina Iyer
2014-09-29 23:02 ` Stephen Boyd
2014-09-27 0:58 ` [PATCH v7 3/7] arm: dts: qcom: Add SPM device bindings for 8084 Lina Iyer
2014-09-30 17:31 ` Kevin Hilman
2014-09-27 0:58 ` [PATCH v7 4/7] qcom: pm: Add cpu low power mode functions Lina Iyer
2014-09-27 8:22 ` Pramod Gurav
2014-09-29 23:37 ` Stephen Boyd
2014-09-30 16:03 ` Lina Iyer
2014-09-30 17:35 ` Kevin Hilman
2014-10-02 0:10 ` Stephen Boyd
2014-10-02 9:50 ` Lorenzo Pieralisi
2014-10-06 17:10 ` Lina Iyer [this message]
2014-09-27 0:58 ` [PATCH v7 5/7] qcom: cpuidle: Add cpuidle driver for QCOM cpus Lina Iyer
2014-09-27 8:18 ` Pramod Gurav
2014-09-29 10:31 ` Pramod Gurav
2014-09-29 15:04 ` Lina Iyer
2014-09-29 15:31 ` Lorenzo Pieralisi
2014-09-29 16:16 ` Lina Iyer
2014-09-29 17:22 ` Lorenzo Pieralisi
2014-09-30 17:41 ` Kevin Hilman
2014-09-30 17:51 ` Nicolas Pitre
2014-09-30 18:06 ` Kevin Hilman
2014-09-30 18:30 ` Nicolas Pitre
2014-09-30 18:41 ` Kevin Hilman
2014-09-30 20:36 ` Lina Iyer
2014-09-29 23:18 ` Stephen Boyd
2014-09-30 8:58 ` Lorenzo Pieralisi
2014-09-30 15:46 ` Lina Iyer
2014-09-30 15:41 ` Lina Iyer
2014-09-27 0:58 ` [PATCH v7 6/7] arm: dts: qcom: Add idle states device nodes for 8974 Lina Iyer
2014-09-27 0:58 ` [PATCH v7 7/7] arm: dts: qcom: Add idle states device nodes for 8084 Lina Iyer
2014-09-29 12:21 ` [PATCH v7 0/7] QCOM 8974 and 8084 cpuidle driver Pramod Gurav
2014-09-29 15:05 ` Lina Iyer
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