Re: [Patch v3 3/6] cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: 2021-07-09 06:46:51
Also in:
linux-arm-msm, linux-pm, lkml
On 08-07-21, 08:06, Thara Gopinath wrote:
quoted hunk ↗ jump to hunk
static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) { struct platform_device *pdev = cpufreq_get_driver_data();@@ -370,6 +480,10 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) dev_warn(cpu_dev, "failed to enable boost: %d\n", ret); } + ret = qcom_cpufreq_hw_lmh_init(policy, index);
You missed unregistering EM here (which is also missing from exit, which you need to fix first in a separate patch).
quoted hunk ↗ jump to hunk
+ if (ret) + goto error; + return 0; error: kfree(data);@@ -389,6 +503,10 @@ static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy) dev_pm_opp_remove_all_dynamic(cpu_dev); dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); + if (data->lmh_dcvs_irq > 0) { + devm_free_irq(cpu_dev, data->lmh_dcvs_irq, data);
Why using devm variants here and while requesting the irq ?
+ cancel_delayed_work_sync(&data->lmh_dcvs_poll_work); + }
Please move this to qcom_cpufreq_hw_lmh_exit() or something.
Now with sequence of disabling interrupt, etc, I see a potential
problem.
CPU0 CPU1
qcom_cpufreq_hw_cpu_exit()
-> devm_free_irq();
qcom_lmh_dcvs_poll()
-> qcom_lmh_dcvs_notify()
-> enable_irq()
-> cancel_delayed_work_sync();
What will happen if enable_irq() gets called after freeing the irq ?
Not sure, but it looks like you will hit this then from manage.c:
WARN(!desc->irq_data.chip, KERN_ERR "enable_irq before
setup/request_irq: irq %u\n", irq))
?
You got a chicken n egg problem :)
--
viresh