Re: [PATCH 1/2] usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller()

From: Felipe Balbi
Date: Fri Jun 29 2018 - 02:38:04 EST



Hi,

Robert Jarzmik <robert.jarzmik@xxxxxxx> writes:

> Jia-Ju Bai <baijiaju1990@xxxxxxxxx> writes:
>
>> The driver may sleep with holding a spinlock.
>> The function call paths (from bottom to top) in Linux-4.16.7 are:
>>
>> [FUNC] msleep
>> drivers/usb/gadget/udc/r8a66597-udc.c, 839:
>> msleep in init_controller
>> drivers/usb/gadget/udc/r8a66597-udc.c, 96:
>> init_controller in r8a66597_usb_disconnect
>> drivers/usb/gadget/udc/r8a66597-udc.c, 93:
>> spin_lock in r8a66597_usb_disconnect
>
> That should not happen...
>
> If think the issue you have is that your usb_connect() and usb_disconnect() are
> called from interrupt context. I think the proper fix, as what is done in most
> udc phys, is to schedule a workqueue, see drivers/usb/phy/phy-gpio-vbus-usb.c,
> gpio_vbus_data.vbus.

argh, no. No workqueues needed here. Sorry

--
balbi