Re: [PATCH] usb: dwc2: Revert "usb: dwc2: Disable all EP's on disconnect"

Dan Carpenter
2018-12-06T14:52:56Z

Hi Marek,

I'm surprised you don't get deadlocks when you apply this patch.

On Wed, Nov 21, 2018 at 04:45:04PM +0100, Marek Szyprowski wrote:

> @@ -4020,9 +4008,7 @@ static int dwc2_hsotg_ep_disable(struct usb_ep *ep)
>
> epctrl_reg = dir_in ? DIEPCTL(index) : DOEPCTL(index);
>
> - locked = spin_is_locked(&hsotg->lock);
> - if (!locked)
> - spin_lock_irqsave(&hsotg->lock, flags);
> + spin_lock_irqsave(&hsotg->lock, flags);
>

One of the callers is already holding the hsotg->log. The
spin_is_locked() test would avoid the deadlock.

regards,
dan carpenter