On Fri, May 29, 2020 at 08:10:40AM +0000, Peter Chen wrote: > On 20-05-28 20:30:28, Michał Mirosław wrote: > > Make debugging real problems easier by not trying to disable an EP that > > was not yet enabled. > > > > Fixes: 4aab757ca44a ("usb: gadget: f_acm: eliminate abuse of ep->driver data") > > Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx> > > --- > > drivers/usb/gadget/function/f_acm.c | 8 +++++--- > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/usb/gadget/function/f_acm.c b/drivers/usb/gadget/function/f_acm.c > > index 200596ea9557..46647bfac2ef 100644 > > --- a/drivers/usb/gadget/function/f_acm.c > > +++ b/drivers/usb/gadget/function/f_acm.c > > @@ -425,9 +425,11 @@ static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt) > > /* we know alt == 0, so this is an activation or a reset */ > > > > if (intf == acm->ctrl_id) { > > - dev_vdbg(&cdev->gadget->dev, > > - "reset acm control interface %d\n", intf); > > - usb_ep_disable(acm->notify); > > + if (acm->notify->enabled) { > > + dev_vdbg(&cdev->gadget->dev, > > + "reset acm control interface %d\n", intf); > > + usb_ep_disable(acm->notify); > > + } > > But it does not fix any issues, the usb_ep_disable checks 'enabled' flag. It generates spurious trace events if you enable them. Best Regards, Michał Mirosław