Hi, Wesley Cheng <wcheng@xxxxxxxxxxxxxx> writes: > There is a race present where the DWC3 runtime resume runs in parallel > to the UDC unbind sequence. This will eventually lead to a possible > scenario where we are enabling the run/stop bit, without a valid > composition defined. > > Thread#1 (handling UDC unbind): > usb_gadget_remove_driver() > -->usb_gadget_disconnect() > -->dwc3_gadget_pullup(0) > --> continue UDC unbind sequence > -->Thread#2 is running in parallel here > > Thread#2 (handing next cable connect) > __dwc3_set_mode() > -->pm_runtime_get_sync() > -->dwc3_gadget_resume() > -->dwc->gadget_driver is NOT NULL yet > -->dwc3_gadget_run_stop(1) > --> _dwc3gadget_start() > ... > > Fix this by tracking the pullup disable routine, and avoiding resuming > of the DWC3 gadget. Once the UDC is re-binded, that will trigger the > pullup enable routine, which would handle enabling the DWC3 gadget. > > Signed-off-by: Wesley Cheng <wcheng@xxxxxxxxxxxxxx> This looks okay to me, but needs to be tested by a few folks ;-) Acked-by: Felipe Balbi <balbi@xxxxxxxxxx> -- balbi
