[PATCH 01/11] usb: chipidea: Add power management support

[Lothar Waßmann]

Hi,

Peter Chen wrote:
> This commit adds runtime and system power management support for
> chipidea core. The runtime pm support is controlled by glue
> layer, it can be enabled by flag CI_HDRC_SUPPORTS_RUNTIME_PM.
> 
[...]
> +#ifdef CONFIG_PM
> +static int ci_controller_suspend(struct device *dev)
> +{
> +	struct ci_hdrc *ci = dev_get_drvdata(dev);
> +
> +	dev_dbg(dev, "at %s\n", __func__);
> +
> +	if (atomic_read(&ci->in_lpm))
> +		return 0;
> +
What does this 'atomic_read()' buy you over just testing/assinging a
simple integer. Note that just because the function has 'atomic' in
its name the sequence:
	atomic_read();
...
	atomic_set();
does not magically become an atomic operation.


Lothar Waßmann
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