[PATCH v4 02/24] PM / devfreq: tegra30: Keep interrupt disabled while governor is stopped

Dmitry Osipenko
2019-07-07T22:35:12Z

There is no real need to keep interrupt always-enabled, will be nicer
to keep it disabled while governor is inactive.

Suggested-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/devfreq/tegra30-devfreq.c | 43 ++++++++++++++++---------------
1 file changed, 22 insertions(+), 21 deletions(-)

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index a27300f40b0b..5e2b133babdd 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -11,6 +11,7 @@
#include <linux/devfreq.h>
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/irq.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
@@ -416,8 +417,6 @@ static void tegra_actmon_start(struct tegra_devfreq *tegra)
{
unsigned int i;

- disable_irq(tegra->irq);
-
actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
ACTMON_GLB_PERIOD_CTRL);

@@ -442,8 +441,6 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra)
}

actmon_write_barrier(tegra);
-
- enable_irq(tegra->irq);
}

static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
@@ -552,6 +549,12 @@ static int tegra_governor_event_handler(struct devfreq *devfreq,
{
struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent);

+ /*
+ * Couple device with the governor early as it is needed at
+ * the moment of governor's start (used by ISR).
+ */
+ tegra->devfreq = devfreq;
+
switch (event) {
case DEVFREQ_GOV_START:
devfreq_monitor_start(devfreq);
@@ -586,10 +589,11 @@ static struct devfreq_governor tegra_devfreq_governor = {

static int tegra_devfreq_probe(struct platform_device *pdev)
{
- struct tegra_devfreq *tegra;
struct tegra_devfreq_device *dev;
- unsigned int i;
+ struct tegra_devfreq *tegra;
+ struct devfreq *devfreq;
unsigned long rate;
+ unsigned int i;
int err;

tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
@@ -625,6 +629,16 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
}
tegra->irq = err;

+ irq_set_status_flags(tegra->irq, IRQ_NOAUTOEN);
+
+ err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
+ actmon_thread_isr, IRQF_ONESHOT,
+ "tegra-devfreq", tegra);
+ if (err) {
+ dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
+ return err;
+ }
+
reset_control_assert(tegra->reset);

err = clk_prepare_enable(tegra->clock);
@@ -672,28 +686,15 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
}

tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
- tegra->devfreq = devfreq_add_device(&pdev->dev,
- &tegra_devfreq_profile,
- "tegra_actmon",
- NULL);
+ devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,
+ "tegra_actmon", NULL);
if (IS_ERR(tegra->devfreq)) {
err = PTR_ERR(tegra->devfreq);
goto remove_governor;
}

- err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
- actmon_thread_isr, IRQF_ONESHOT,
- "tegra-devfreq", tegra);
- if (err) {
- dev_err(&pdev->dev, "Interrupt request failed: %d\n", err);
- goto remove_devfreq;
- }
-
return 0;

-remove_devfreq:
- devfreq_remove_device(tegra->devfreq);
-
remove_governor:
devfreq_remove_governor(&tegra_devfreq_governor);

--
2.22.0