| Message ID | 20190417222925.5815-8-digetx@gmail.com |
|---|---|
| State | Deferred |
| Headers | show |
| Series | NVIDIA Tegra devfreq improvements and Tegra20/30 support | expand |
On 19. 4. 18. 오전 7:29, Dmitry Osipenko wrote: > 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. > > 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) { > It is ok to disable the hardware interrupt line before completing the some operation about registers in order to protect the interrupt occur. Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
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) {
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. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- drivers/devfreq/tegra-devfreq.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-)