Messages in this thread Patch in this message | | | Date | Thu, 29 Jul 2021 11:47:13 +0530 | From | Viresh Kumar <> | Subject | Re: [Patch v4 3/6] cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support |
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On 28-07-21, 18:19, Thara Gopinath wrote: > Ha! I was too lazy to write this down! So how about I make this a mutex and
mutex may not work as you come here from irq.
> put mod_delayed_work() inside the lock. So it will be something like below > > qcom_lmh_dcvs_notify() qcom_cpufreq_hw_lmh_exit() > > mutex_lock() mutex_lock() > if (data->cancel_throttle) { cancel_throttle = true > mutex_unlock() mutex_unlock() > return cancel_delayed_work_sync() > } free_irq() > enable_irq() / mod_delayed_work() > mutex_unlock() > > I will let you break it!
I can't any further :)
Consider merging below to this patch, it fixes sever other minor issues I see in the code.
-- viresh
-------------------------8<-------------------------
diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c index 3cc27d9e2ed1..4261299fa9e5 100644 --- a/drivers/cpufreq/qcom-cpufreq-hw.c +++ b/drivers/cpufreq/qcom-cpufreq-hw.c @@ -38,13 +38,17 @@ struct qcom_cpufreq_soc_data { struct qcom_cpufreq_data { void __iomem *base; struct resource *res; - struct delayed_work throttle_work; const struct qcom_cpufreq_soc_data *soc_data; - struct cpufreq_policy *policy; - /* Lock to synchronize between de-init sequence and re-starting LMh polling/interrupts */ + + /* + * Lock to synchronize between de-init sequence and re-starting LMh + * polling/interrupts. + */ spinlock_t throttle_lock; int throttle_irq; bool cancel_throttle; + struct delayed_work throttle_work; + struct cpufreq_policy *policy; };
static unsigned long cpu_hw_rate, xo_rate; @@ -271,10 +275,11 @@ static unsigned int qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data) { + unsigned long max_capacity, capacity, freq_hz, throttled_freq; struct cpufreq_policy *policy = data->policy; + int cpu = cpumask_first(policy->cpus); + struct device *dev = get_cpu_device(cpu); struct dev_pm_opp *opp; - struct device *dev; - unsigned long max_capacity, capacity, freq_hz, throttled_freq; unsigned int freq;
/* @@ -284,7 +289,6 @@ static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data) freq = qcom_lmh_get_throttle_freq(data); freq_hz = freq * HZ_PER_KHZ;
- dev = get_cpu_device(cpumask_first(policy->cpus)); opp = dev_pm_opp_find_freq_floor(dev, &freq_hz); if (IS_ERR(opp) && PTR_ERR(opp) == -ERANGE) opp = dev_pm_opp_find_freq_ceil(dev, &freq_hz); @@ -293,34 +297,37 @@ static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
/* Update thermal pressure */
- max_capacity = arch_scale_cpu_capacity(cpumask_first(policy->cpus)); + max_capacity = arch_scale_cpu_capacity(cpu); capacity = mult_frac(max_capacity, throttled_freq, policy->cpuinfo.max_freq); + /* Don't pass boost capacity to scheduler */ if (capacity > max_capacity) capacity = max_capacity;
arch_set_thermal_pressure(policy->cpus, max_capacity - capacity);
- /* In the unlikely case cpufreq is de-registered do not enable polling or h/w interrupt */ - + /* + * In the unlikely case, where the policy is going away, do not enable + * polling or h/w interrupt. + */ spin_lock(&data->throttle_lock); - if (data->cancel_throttle) { - spin_unlock(&data->throttle_lock); - return; - } - spin_unlock(&data->throttle_lock); + + if (data->cancel_throttle) + goto out;
/* - * If h/w throttled frequency is higher than what cpufreq has requested for, stop - * polling and switch back to interrupt mechanism + * If h/w throttled frequency is higher than what cpufreq has requested + * for, then stop polling and switch back to interrupt mechanism. */
- if (throttled_freq >= qcom_cpufreq_hw_get(cpumask_first(policy->cpus))) - /* Clear the existing interrupts and enable it back */ + if (throttled_freq >= qcom_cpufreq_hw_get(cpu)) { enable_irq(data->throttle_irq); - else + } else { mod_delayed_work(system_highpri_wq, &data->throttle_work, msecs_to_jiffies(10)); + } +out: + spin_unlock(&data->throttle_lock); }
static void qcom_lmh_dcvs_poll(struct work_struct *work) @@ -328,7 +335,6 @@ static void qcom_lmh_dcvs_poll(struct work_struct *work) struct qcom_cpufreq_data *data;
data = container_of(work, struct qcom_cpufreq_data, throttle_work.work); - qcom_lmh_dcvs_notify(data); }
@@ -407,6 +413,7 @@ static void qcom_cpufreq_hw_lmh_exit(struct qcom_cpufreq_data *data) spin_lock(&data->throttle_lock); data->cancel_throttle = true; spin_unlock(&data->throttle_lock); + cancel_delayed_work_sync(&data->throttle_work); free_irq(data->throttle_irq, data); }
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