Re: [PACTH v3 1/2] usb: xhci: plat: Enable runtime PM

[Robert Foss]

On 2016-08-09 05:19 AM, Felipe Balbi wrote:
> Hi,
>
> robert.foss@xxxxxxxxxxxxx writes:
> > From: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
> >
> > Enable runtime PM for the xhci-plat device so that the parent device
> > may implement runtime PM.
> >
> > Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
> > Tested-by: Robert Foss <robert.foss@xxxxxxxxxxxxx>
> > Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxxxxx>
> > ---
> >  drivers/usb/host/xhci-plat.c | 24 ++++++++++++++++++++++--
> >  1 file changed, 22 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> > index ed56bf9..4f39d4e 100644
> > --- a/drivers/usb/host/xhci-plat.c
> > +++ b/drivers/usb/host/xhci-plat.c
> > @@ -246,6 +246,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
> >  	if (ret)
> >  		goto dealloc_usb2_hcd;
> >
> > +	pm_runtime_set_active(&pdev->dev);
> > +	pm_runtime_enable(&pdev->dev);
> > +
> >  	return 0;
> >
> >
> > @@ -274,6 +277,8 @@ static int xhci_plat_remove(struct platform_device *dev)
> >  	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
> >  	struct clk *clk = xhci->clk;
> >
> > +	pm_runtime_disable(&dev->dev);
> > +
> >  	usb_remove_hcd(xhci->shared_hcd);
> >  	usb_phy_shutdown(hcd->usb_phy);
> >
> > @@ -292,7 +297,11 @@ static int xhci_plat_suspend(struct device *dev)
> >  {
> >  	struct usb_hcd	*hcd = dev_get_drvdata(dev);
> >  	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
> > +	int ret;
> >
> > +	ret = pm_runtime_get_sync(dev);
> > +	if (ret < 0)
> > +		return ret;
>
> you're leaving unbalanced PM usage_counter here. If pm_runtime_get*()
> fails, you still have to decrement usage_counter.
>
> >  	/*
> >  	 * xhci_suspend() needs `do_wakeup` to know whether host is allowed
> >  	 * to do wakeup during suspend. Since xhci_plat_suspend is currently
> > @@ -301,15 +310,26 @@ static int xhci_plat_suspend(struct device *dev)
> >  	 * reconsider this when xhci_plat_suspend enlarges its scope, e.g.,
> >  	 * also applies to runtime suspend.
> >  	 */
> > -	return xhci_suspend(xhci, device_may_wakeup(dev));
> > +	ret = xhci_suspend(xhci, device_may_wakeup(dev));
> > +	pm_runtime_put(dev);
> > +
> > +	return ret;
> >  }
> >
> >  static int xhci_plat_resume(struct device *dev)
> >  {
> >  	struct usb_hcd	*hcd = dev_get_drvdata(dev);
> >  	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
> > +	int ret;
> > +
> > +	ret = pm_runtime_get_sync(dev);
> > +	if (ret < 0)
> > +		return ret;
>
> ditto

Thanks Filipe!
I'll be submitting a v4 as soon as testing has completed.