Re: [PATCH] usb: dwc3: gadget: Restart DWC3 gadget when enabling pullup

[Michael Tretter]

On Thu, 19 Nov 2020 16:13:21 -0800, Wesley Cheng wrote:
> usb_gadget_deactivate/usb_gadget_activate does not execute the UDC start
> operation, which may leave EP0 disabled and event IRQs disabled when
> re-activating the function. Move the enabling/disabling of USB EP0 and
> device event IRQs to be performed in the pullup routine.
> 
> Fixes: ae7e86108b12 ("usb: dwc3: Stop active transfers before halting the
> controller")
> 
> Reported-by: Michael Tretter <m.tretter@xxxxxxxxxxxxxx>
> Signed-off-by: Wesley Cheng <wcheng@xxxxxxxxxxxxxx>

Tested-by: Michael Tretter <m.tretter@xxxxxxxxxxxxxx>

> ---
>  drivers/usb/dwc3/gadget.c | 14 +++-----------
>  1 file changed, 3 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 5d879b7606d5..922c8b76e534 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1988,6 +1988,7 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
>  
>  static void dwc3_gadget_disable_irq(struct dwc3 *dwc);
>  static void __dwc3_gadget_stop(struct dwc3 *dwc);
> +static int __dwc3_gadget_start(struct dwc3 *dwc);
>  
>  static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
>  {
> @@ -2050,6 +2051,8 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
>  			dwc->ev_buf->lpos = (dwc->ev_buf->lpos + count) %
>  						dwc->ev_buf->length;
>  		}
> +	} else {
> +		__dwc3_gadget_start(dwc);
>  	}
>  
>  	ret = dwc3_gadget_run_stop(dwc, is_on, false);
> @@ -2224,10 +2227,6 @@ static int dwc3_gadget_start(struct usb_gadget *g,
>  	}
>  
>  	dwc->gadget_driver	= driver;
> -
> -	if (pm_runtime_active(dwc->dev))
> -		__dwc3_gadget_start(dwc);
> -
>  	spin_unlock_irqrestore(&dwc->lock, flags);
>  
>  	return 0;
> @@ -2253,13 +2252,6 @@ static int dwc3_gadget_stop(struct usb_gadget *g)
>  	unsigned long		flags;
>  
>  	spin_lock_irqsave(&dwc->lock, flags);
> -
> -	if (pm_runtime_suspended(dwc->dev))
> -		goto out;
> -
> -	__dwc3_gadget_stop(dwc);
> -
> -out:
>  	dwc->gadget_driver	= NULL;
>  	spin_unlock_irqrestore(&dwc->lock, flags);
>  
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 
>