Re: [PATCH] kthread: Unpark only parked kthreads (was Re: [syzbot] [wireguard?] WARNING in kthread_unpark (2))

[Hillf Danton <hdanton@sina.com>]

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On Fri, 13 Sep 2024 14:31:52 +0200 Frederic Weisbecker <frederic@kernel.org>
> Le Fri, Sep 13, 2024 at 08:11:09PM +0800, Hillf Danton a écrit :
> 
> But are the following bits deliberate?
> 
It is added to kill rcu stall [1,2] and win Tested-by.

[1] https://lore.kernel.org/lkml/000000000000e6ca5d0621ece2dc@google.com/
[2] https://lore.kernel.org/lkml/0000000000008de5720617f64aae@google.com/

> > --- l/drivers/input/misc/yealink.c
> > +++ y/drivers/input/misc/yealink.c
> > @@ -438,7 +438,7 @@ static void urb_irq_callback(struct urb
> >  
> >  	yealink_do_idle_tasks(yld);
> >  
> > -	if (!yld->shutdown) {
> > +	if (!yld->shutdown && status != -EPROTO) {
> >  		ret = usb_submit_urb(yld->urb_ctl, GFP_ATOMIC);
> >  		if (ret && ret != -EPERM)
> >  			dev_err(&yld->intf->dev,
> > @@ -460,13 +460,13 @@ static void urb_ctl_callback(struct urb
> >  	case CMD_KEYPRESS:
> >  	case CMD_SCANCODE:
> >  		/* ask for a response */
> > -		if (!yld->shutdown)
> > +		if (!yld->shutdown && status != -EPROTO)
> >  			ret = usb_submit_urb(yld->urb_irq, GFP_ATOMIC);
> >  		break;
> >  	default:
> >  		/* send new command */
> >  		yealink_do_idle_tasks(yld);
> > -		if (!yld->shutdown)
> > +		if (!yld->shutdown && status != -EPROTO)
> >  			ret = usb_submit_urb(yld->urb_ctl, GFP_ATOMIC);
> >  		break;
> >  	}
> > --