On Tue 2014-11-04 13:52:48, Krzysztof Kozlowski wrote:
> The AMBA bus driver defines runtime Power Management functions which
> disable and unprepare AMBA bus clock. This is problematic for runtime PM
> because unpreparing a clock might sleep so it is not interrupt safe.
>
> However some drivers may want to implement runtime PM functions in
> interrupt-safe way (see pm_runtime_irq_safe()). In such case the AMBA
> bus driver should only disable/enable the clock in runtime suspend and
> resume callbacks.
> /*
> * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
> * enable/disable the bus clock at runtime PM suspend/resume as this
> @@ -95,8 +102,14 @@ static int amba_pm_runtime_suspend(struct device *dev)
> struct amba_device *pcdev = to_amba_device(dev);
> int ret = pm_generic_runtime_suspend(dev);
>
> - if (ret == 0 && dev->driver)
> - clk_disable_unprepare(pcdev->pclk);
> + if (ret == 0 && dev->driver) {
> + pcdev->irq_safe = get_pm_runtime_irq_safe(dev);
> +
> + if (pcdev->irq_safe)
> + clk_disable(pcdev->pclk);
> + else
> + clk_disable_unprepare(pcdev->pclk);
> + }
So you can handle the case of !pcdev->irq_safe. What is the penalty
for always assuming !pcdev->irq_safe?
Pavel
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