PM / devfreq: tegra: Drop primary interrupt handler

There is no real need in the primary interrupt handler, hence move
everything to the secondary (threaded) handler. In a result locking
is consistent now and there are no potential races with the interrupt
handler because it is protected with the devfreq's mutex.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
index 6780fb4..b923d21 100644 (file)
--- a/drivers/devfreq/tegra-devfreq.c
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -132,7 +132,6 @@ static struct tegra_devfreq_device_config actmon_device_configs[] = {
 struct tegra_devfreq_device {
        const struct tegra_devfreq_device_config *config;
        void __iomem *regs;
-       spinlock_t lock;
 
        /* Average event count sampled in the last interrupt */
        u32 avg_count;
@@ -237,11 +236,8 @@ static void actmon_write_barrier(struct tegra_devfreq *tegra)
 static void actmon_isr_device(struct tegra_devfreq *tegra,
                              struct tegra_devfreq_device *dev)
 {
-       unsigned long flags;
        u32 intr_status, dev_ctrl;
 
-       spin_lock_irqsave(&dev->lock, flags);
-
        dev->avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT);
        tegra_devfreq_update_avg_wmark(tegra, dev);
 
@@ -290,26 +286,6 @@ static void actmon_isr_device(struct tegra_devfreq *tegra,
        device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);
 
        actmon_write_barrier(tegra);
-
-       spin_unlock_irqrestore(&dev->lock, flags);
-}
-
-static irqreturn_t actmon_isr(int irq, void *data)
-{
-       struct tegra_devfreq *tegra = data;
-       bool handled = false;
-       unsigned int i;
-       u32 val;
-
-       val = actmon_readl(tegra, ACTMON_GLB_STATUS);
-       for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
-               if (val & tegra->devices[i].config->irq_mask) {
-                       actmon_isr_device(tegra, tegra->devices + i);
-                       handled = true;
-               }
-       }
-
-       return handled ? IRQ_WAKE_THREAD : IRQ_NONE;
 }
 
 static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra,
@@ -336,15 +312,12 @@ static void actmon_update_target(struct tegra_devfreq *tegra,
        unsigned long cpu_freq = 0;
        unsigned long static_cpu_emc_freq = 0;
        unsigned int avg_sustain_coef;
-       unsigned long flags;
 
        if (dev->config->avg_dependency_threshold) {
                cpu_freq = cpufreq_get(0);
                static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
        }
 
-       spin_lock_irqsave(&dev->lock, flags);
-
        dev->target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD;
        avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;
        dev->target_freq = do_percent(dev->target_freq, avg_sustain_coef);
@@ -352,19 +325,31 @@ static void actmon_update_target(struct tegra_devfreq *tegra,
 
        if (dev->avg_count >= dev->config->avg_dependency_threshold)
                dev->target_freq = max(dev->target_freq, static_cpu_emc_freq);
-
-       spin_unlock_irqrestore(&dev->lock, flags);
 }
 
 static irqreturn_t actmon_thread_isr(int irq, void *data)
 {
        struct tegra_devfreq *tegra = data;
+       bool handled = false;
+       unsigned int i;
+       u32 val;
 
        mutex_lock(&tegra->devfreq->lock);
-       update_devfreq(tegra->devfreq);
+
+       val = actmon_readl(tegra, ACTMON_GLB_STATUS);
+       for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+               if (val & tegra->devices[i].config->irq_mask) {
+                       actmon_isr_device(tegra, tegra->devices + i);
+                       handled = true;
+               }
+       }
+
+       if (handled)
+               update_devfreq(tegra->devfreq);
+
        mutex_unlock(&tegra->devfreq->lock);
 
-       return IRQ_HANDLED;
+       return handled ? IRQ_HANDLED : IRQ_NONE;
 }
 
 static int tegra_actmon_rate_notify_cb(struct notifier_block *nb,
@@ -374,7 +359,6 @@ static int tegra_actmon_rate_notify_cb(struct notifier_block *nb,
        struct tegra_devfreq *tegra;
        struct tegra_devfreq_device *dev;
        unsigned int i;
-       unsigned long flags;
 
        if (action != POST_RATE_CHANGE)
                return NOTIFY_OK;
@@ -386,9 +370,7 @@ static int tegra_actmon_rate_notify_cb(struct notifier_block *nb,
        for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
                dev = &tegra->devices[i];
 
-               spin_lock_irqsave(&dev->lock, flags);
                tegra_devfreq_update_wmark(tegra, dev);
-               spin_unlock_irqrestore(&dev->lock, flags);
        }
 
        actmon_write_barrier(tegra);
@@ -670,7 +652,6 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
                dev = tegra->devices + i;
                dev->config = actmon_device_configs + i;
                dev->regs = tegra->regs + dev->config->offset;
-               spin_lock_init(&dev->lock);
 
                tegra_actmon_configure_device(tegra, dev);
        }
@@ -688,8 +669,8 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
 
        platform_set_drvdata(pdev, tegra);
 
-       err = devm_request_threaded_irq(&pdev->dev, irq, actmon_isr,
-                                       actmon_thread_isr, IRQF_SHARED,
+       err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+                                       actmon_thread_isr, IRQF_ONESHOT,
                                        "tegra-devfreq", tegra);
        if (err) {
                dev_err(&pdev->dev, "Interrupt request failed\n");