[PATCH v4 07/16] PM / devfreq: tegra: Properly disable interrupts

Dmitry Osipenko
2019-05-01T23:42:46Z

There is no guarantee that interrupt handling isn't running in parallel
with tegra_actmon_disable_interrupts(), hence it is necessary to protect
DEV_CTRL register accesses and clear IRQ status with ACTMON's IRQ being
disabled in the Interrupt Controller in order to ensure that device
interrupt is indeed being disabled.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/devfreq/tegra-devfreq.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
index b65313fe3c2e..ce1eb97a2090 100644
--- a/drivers/devfreq/tegra-devfreq.c
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -171,6 +171,8 @@ struct tegra_devfreq {
struct notifier_block rate_change_nb;

struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)];
+
+ int irq;
};

struct tegra_actmon_emc_ratio {
@@ -417,6 +419,8 @@ static void tegra_actmon_disable_interrupts(struct tegra_devfreq *tegra)
u32 val;
unsigned int i;

+ disable_irq(tegra->irq);
+
for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
dev = &tegra->devices[i];

@@ -427,9 +431,14 @@ static void tegra_actmon_disable_interrupts(struct tegra_devfreq *tegra)
val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;

device_writel(dev, val, ACTMON_DEV_CTRL);
+
+ device_writel(dev, ACTMON_INTR_STATUS_CLEAR,
+ ACTMON_DEV_INTR_STATUS);
}

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

static void tegra_actmon_configure_device(struct tegra_devfreq *tegra,
@@ -604,7 +613,6 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
struct resource *res;
unsigned int i;
unsigned long rate;
- int irq;
int err;

tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
@@ -673,15 +681,16 @@ static int tegra_devfreq_probe(struct platform_device *pdev)
dev_pm_opp_add(&pdev->dev, rate, 0);
}

- irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "Failed to get IRQ: %d\n", irq);
- return irq;
+ tegra->irq = platform_get_irq(pdev, 0);
+ if (tegra->irq < 0) {
+ err = tegra->irq;
+ dev_err(&pdev->dev, "Failed to get IRQ: %d\n", err);
+ return err;
}

platform_set_drvdata(pdev, tegra);

- err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+ err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL,
actmon_thread_isr, IRQF_ONESHOT,
"tegra-devfreq", tegra);
if (err) {
--
2.21.0