[PATCH v4 06/16] PM / devfreq: tegra: Drop primary interrupt handler

Dmitry Osipenko
2019-05-01T23:42:04Z

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>
---
drivers/devfreq/tegra-devfreq.c | 55 +++++++++++----------------------
1 file changed, 18 insertions(+), 37 deletions(-)

diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
index 24ec65556c39..b65313fe3c2e 100644
--- a/drivers/devfreq/tegra-devfreq.c
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -144,7 +144,6 @@ 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;
@@ -249,11 +248,8 @@ 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);

@@ -302,26 +298,6 @@ 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,
@@ -348,15 +324,12 @@ 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);
@@ -364,19 +337,31 @@ 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,
@@ -386,7 +371,6 @@ 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;
@@ -398,9 +382,7 @@ 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);
@@ -682,7 +664,6 @@ 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);
}
@@ -700,8 +681,8 @@ 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");
--
2.21.0