Hello Alan Stern,
The patch 1016fc0c096c: "USB: gadget: Fix obscure lockdep violation
for udc_mutex" from Aug 26, 2022, leads to the following Smatch
static checker warning:
drivers/usb/gadget/udc/core.c:767 usb_gadget_disconnect()
warn: sleeping in atomic context
drivers/usb/gadget/udc/core.c
757 * Gadget will stay disconnected after activation.
758 */
759 gadget->connected = false;
760 goto out;
761 }
762
763 ret = gadget->ops->pullup(gadget, 0);
764 if (!ret)
765 gadget->connected = 0;
766
--> 767 mutex_lock(&udc_lock);
768 if (gadget->udc->driver)
769 gadget->udc->driver->disconnect(gadget);
770 mutex_unlock(&udc_lock);
771
The call tree where we're holding a spinlock is:
max3420_vbus_handler() <- disables preempt
-> usb_udc_vbus_handler()
-> usb_udc_connect_control()
-> usb_gadget_disconnect()
regards,
dan carpenter
