Re: [PATCH] usb: dwc3: gadget: call gadget driver's ->suspend/->resume

[Felipe Balbi <balbi@ti.com>]

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On Fri, Apr 17, 2015 at 11:41:56AM -0700, David Cohen wrote:
> From: Felipe Balbi <balbi@ti.com>

missing the required:

[ Upstream commit bc5ba2e0b829c9397f96df1191c7d2319ebc36d9 ]

> 
> When going into bus suspend/resume we _must_
> call gadget driver's ->suspend/->resume callbacks
> accordingly. This patch implements that very feature
> which has been missing forever.
> 
> Cc: <stable@vger.kernel.org> # 3.14
> Signed-off-by: Felipe Balbi <balbi@ti.com>
> Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
> ---
> 
> Hi,
> 
> This patch was introduced on v3.15.
> But the issue it fixes already existed on v3.14 and v3.14 is a long term
> support version.

Can you show me a log of this breaking anywhere ? Why do you consider
this a bug fix ? What sort of drawbacks did you notice ?

> I propose to backport it over there as well.
> 
> BR, David
> ---
> 
>  drivers/usb/dwc3/gadget.c | 35 +++++++++++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 8f6738d46b14..1bb752736c32 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2012,6 +2012,24 @@ static void dwc3_disconnect_gadget(struct dwc3 *dwc)
>  	}
>  }
>  
> +static void dwc3_suspend_gadget(struct dwc3 *dwc)
> +{
> +	if (dwc->gadget_driver && dwc->gadget_driver->disconnect) {

you also need Dan Carperter's commit which fixes this cut & paste error.
That's commit 73a30bfc0d526db899033165db6f95c427e70505

> +		spin_unlock(&dwc->lock);
> +		dwc->gadget_driver->suspend(&dwc->gadget);
> +		spin_lock(&dwc->lock);
> +	}
> +}
> +
> +static void dwc3_resume_gadget(struct dwc3 *dwc)
> +{
> +	if (dwc->gadget_driver && dwc->gadget_driver->disconnect) {
> +		spin_unlock(&dwc->lock);
> +		dwc->gadget_driver->resume(&dwc->gadget);
> +		spin_lock(&dwc->lock);
> +	}
> +}
> +
>  static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum)
>  {
>  	struct dwc3_ep *dep;
> @@ -2391,6 +2409,23 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
>  
>  	dwc->link_state = next;
>  
> +	switch (next) {
> +	case DWC3_LINK_STATE_U1:
> +		if (dwc->speed == USB_SPEED_SUPER)
> +			dwc3_suspend_gadget(dwc);
> +		break;
> +	case DWC3_LINK_STATE_U2:
> +	case DWC3_LINK_STATE_U3:
> +		dwc3_suspend_gadget(dwc);
> +		break;
> +	case DWC3_LINK_STATE_RESUME:
> +		dwc3_resume_gadget(dwc);
> +		break;
> +	default:
> +		/* do nothing */
> +		break;
> +	}
> +
>  	dev_vdbg(dwc->dev, "%s link %d\n", __func__, dwc->link_state);
>  }

-- 
balbi

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