Re: [PATCH 6/6] USB: ehci-omap: Implement suspend/resume

From: Alan Stern
Date: Mon Jul 22 2013 - 11:18:53 EST


On Mon, 22 Jul 2013, Roger Quadros wrote:

> Right, I understand it now. How does the below code look?
>
> +static int omap_ehci_suspend(struct device *dev)
> +{
> + struct usb_hcd *hcd = dev_get_drvdata(dev);
> + bool do_wakeup = device_may_wakeup(dev);
> + int ret;
> +
> + dev_dbg(dev, "%s may_wakeup %d\n", __func__, do_wakeup);
> +
> + if (pm_runtime_status_suspended(dev)) {

You need to do this only when do_wakeup is false.

> + pm_runtime_get_sync(dev);
> + ehci_resume(hcd, false);
> + ret = ehci_suspend(hcd, do_wakeup);
> + pm_runtime_put_sync(dev);

It would be better to call pm_runtime_resume(dev) at the start instead
of pm_runtime_get_sync(), and eliminate the last two lines. Then the
ehci_suspend() below could be moved outside the "if" statement.

Alternatively, if you are able to turn off the wakeup setting without
going through an entire resume/suspend cycle, that would be preferable.

> +
> + } else {
> + ret = ehci_suspend(hcd, do_wakeup);
> + }
> +
> + return ret;
> +}
> +
> +static int omap_ehci_resume(struct device *dev)
> +{
> + struct usb_hcd *hcd = dev_get_drvdata(dev);
> + int ret;
> +
> + dev_dbg(dev, "%s\n", __func__);
> +
> + ret = ehci_resume(hcd, false);
> + if (!ret) {
> + /*
> + * Controller was powered ON so reflect state
> + */
> + pm_runtime_disable(dev);
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> + }
> +
> + return ret;
> +}

All good.

Alan Stern

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