From: Robert Jarzmik <robert.jarzmik@free.fr>
To: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: balbi@kernel.org, gregkh@linuxfoundation.org,
nicolas.ferre@microchip.com, keescook@chromium.org,
allen.lkml@gmail.com, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller()
Date: Thu, 21 Jun 2018 11:06:02 +0200 [thread overview]
Message-ID: <87efh0o6f9.fsf@belgarion.home> (raw)
In-Reply-To: <20180620035453.7721-1-baijiaju1990@gmail.com> (Jia-Ju Bai's message of "Wed, 20 Jun 2018 11:54:53 +0800")
Jia-Ju Bai <baijiaju1990@gmail.com> 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.
Cheers.
--
Robert
next prev parent reply other threads:[~2018-06-21 9:06 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-20 3:54 [PATCH 1/2] usb: gadget: r8a66597: Fix two possible sleep-in-atomic-context bugs in init_controller() Jia-Ju Bai
2018-06-21 9:06 ` Robert Jarzmik [this message]
2018-06-29 6:35 ` Felipe Balbi
2018-06-29 6:48 ` Robert Jarzmik
2018-06-29 10:25 ` Felipe Balbi
2018-06-29 11:04 ` Robert Jarzmik
2018-06-29 11:15 ` Felipe Balbi
2018-06-29 13:21 ` Robert Jarzmik
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