> From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Sent: Thursday, September 9, 2021 2:11 PM
> To: Linyu Yuan (QUIC) <quic_linyyuan@xxxxxxxxxxx>
> Cc: Felipe Balbi <balbi@xxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH] usb: dwc3: gadget: clear gadget pointer after exit
>
> On Thu, Sep 09, 2021 at 01:45:47PM +0800, Linyu Yuan wrote:
> > change device release function to clear gadget pointer.
>
> That does not properly describe what and why this change is needed.
>
> >
> > Signed-off-by: Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
> > ---
> > drivers/usb/dwc3/gadget.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> > index 804b505..e2ab5f6 100644
> > --- a/drivers/usb/dwc3/gadget.c
> > +++ b/drivers/usb/dwc3/gadget.c
> > @@ -4188,9 +4188,10 @@ static int dwc3_gadget_get_irq(struct dwc3
> *dwc)
> >
> > static void dwc_gadget_release(struct device *dev)
> > {
> > - struct usb_gadget *gadget = container_of(dev, struct usb_gadget,
> dev);
> > + struct dwc3 *dwc = dev_get_platdata(dev);
>
> Are you sure this is the same?
Yes, in dwc3_gadget_init()
usb_initialize_gadget(dwc->dev, dwc->gadget, dwc_gadget_release);
dev = &dwc->gadget->dev;
dev->platform_data = dwc;
here original code use follow container_of, it use same dev,
container_of(dev, struct usb_gadget, dev);
>
> >
> > - kfree(gadget);
> > + kfree(dwc->gadget);
> > + dwc->gadget = NULL;
>
> Why set this to NULL? Who cares about this now? What changed to make
> it required?
It better to set to NULL for better understanding.
>
> thanks,
>
> greg k-h
