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

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Message-ID: <87k2fqb8ox.fsf@linux.intel.com>
Date:	Tue, 09 Aug 2016 12:19:58 +0300
From:	Felipe Balbi <felipe.balbi@...ux.intel.com>
To:	robert.foss@...labora.com, mathias.nyman@...el.com,
	gregkh@...uxfoundation.org, linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org, Julius Werner <jwerner@...omium.org>,
	Andrew Bresticker <abrestic@...omium.org>
Cc:	Robert Foss <robert.foss@...labora.com>
Subject: Re: [PACTH v3 1/2] usb: xhci: plat: Enable runtime PM


Hi,

robert.foss@...labora.com writes:
> From: Andrew Bresticker <abrestic@...omium.org>
>
> Enable runtime PM for the xhci-plat device so that the parent device
> may implement runtime PM.
>
> Signed-off-by: Andrew Bresticker <abrestic@...omium.org>
> Tested-by: Robert Foss <robert.foss@...labora.com>
> Signed-off-by: Robert Foss <robert.foss@...labora.com>
> ---
>  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

-- 
balbi

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