Re: [PATCH 8/9] usb: dwc2/gadget: fix calls to phy control functions in suspend/resume code

[Felipe Balbi <balbi@ti.com>]

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Hi,

On Thu, Oct 16, 2014 at 02:58:04PM +0200, Marek Szyprowski wrote:
> This patch moves calls to phy enable/disable out of spinlock protected
> blocks in device suspend/resume to fix incorrect caller context. Phy
> related functions must not be called from atomic context.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  drivers/usb/dwc2/gadget.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index cdf417a7ae63..052b1a857291 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -3656,11 +3656,13 @@ static int s3c_hsotg_suspend(struct platform_device *pdev, pm_message_t state)
>  			 hsotg->driver->driver.name);
>  
>  	spin_lock_irqsave(&hsotg->lock, flags);
> +	s3c_hsotg_core_disconnect(hsotg);
>  	s3c_hsotg_disconnect(hsotg);
> -	s3c_hsotg_phy_disable(hsotg);
>  	hsotg->gadget.speed = USB_SPEED_UNKNOWN;
>  	spin_unlock_irqrestore(&hsotg->lock, flags);
>  
> +	s3c_hsotg_phy_disable(hsotg);

this is aching to have a locked version as well as an unlocked version.
Look at what you do here. There's a minor race when you release that
spinlock. By the time ->suspend() is called, IRQs are not yet disabled.

-- 
balbi

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