linux-kernel - Re: [PATCH 3/4] usb: dwc3: exynos: Enable runtime power management

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Date:	Mon, 28 Jan 2013 13:47:55 +0200
From:	Felipe Balbi <balbi@...com>
To:	Vivek Gautam <gautam.vivek@...sung.com>
CC:	<linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<linux-omap@...r.kernel.org>, <linux-samsung-soc@...r.kernel.org>,
	<gregkh@...uxfoundation.org>, <balbi@...com>,
	<sarah.a.sharp@...ux.intel.com>, <kgene.kim@...sung.com>,
	<dianders@...omium.org>, <sylvester.nawrocki@...il.com>,
	<tomasz.figa@...il.com>
Subject: Re: [PATCH 3/4] usb: dwc3: exynos: Enable runtime power management

On Mon, Jan 28, 2013 at 05:12:27PM +0530, Vivek Gautam wrote:
> Enabling runtime power management on dwc3-exynos to save
> power and allow its PHY's power to be managed at runtime.
> 
> Signed-off-by: Vivek Gautam <gautam.vivek@...sung.com>
> ---
>  drivers/usb/dwc3/dwc3-exynos.c |   47 ++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 47 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
> index aae5328..c51e8c1 100644
> --- a/drivers/usb/dwc3/dwc3-exynos.c
> +++ b/drivers/usb/dwc3/dwc3-exynos.c
> @@ -157,11 +157,15 @@ static int dwc3_exynos_probe(struct platform_device *pdev)
>  		goto err4;
>  	}
>  
> +	pm_runtime_set_active(&pdev->dev);
> +	pm_runtime_enable(&pdev->dev);
> +
>  	return 0;
>  
>  err4:
>  	clk_disable(clk);
>  	clk_put(clk);
> +	pm_runtime_disable(&pdev->dev);
>  err3:
>  	platform_device_put(dwc3);
>  err1:
> @@ -174,6 +178,8 @@ static int dwc3_exynos_remove(struct platform_device *pdev)
>  {
>  	struct dwc3_exynos	*exynos = platform_get_drvdata(pdev);
>  
> +	pm_runtime_disable(&pdev->dev);
> +
>  	platform_device_unregister(exynos->dwc3);
>  	platform_device_unregister(exynos->usb2_phy);
>  	platform_device_unregister(exynos->usb3_phy);
> @@ -186,6 +192,46 @@ static int dwc3_exynos_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static int dwc3_exynos_runtime_suspend(struct device *dev)
> +{
> +	struct dwc3_exynos	*exynos = dev_get_drvdata(dev);
> +	struct platform_device	*pdev_dwc = exynos->dwc3;
> +	struct dwc3		*dwc = NULL;
> +
> +	dwc = platform_get_drvdata(pdev_dwc);
> +
> +	if (!dwc)
> +		return 0;
> +
> +	pm_runtime_put_sync(dwc->usb3_phy->dev);
> +
> +	clk_disable(exynos->clk);
> +
> +	return 0;
> +}
> +static int dwc3_exynos_runtime_resume(struct device *dev)
> +{
> +	struct dwc3_exynos	*exynos = dev_get_drvdata(dev);
> +	struct platform_device	*pdev_dwc = exynos->dwc3;
> +	struct dwc3		*dwc = NULL;
> +
> +	dwc = platform_get_drvdata(pdev_dwc);
> +
> +	clk_enable(exynos->clk);
> +
> +	if (!dwc)
> +		return 0;
> +
> +	pm_runtime_get_sync(dwc->usb3_phy->dev);

dude, this is wrong :-)

look at this:

pm_runtime_get() -> dwc3_exynos_runtime_resume() ->
pm_runtime_get_sync() -> dwc3_exynos_runtime_resume() -> ...

only your clock enalbe should do

-- 
balbi

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