From: Alan Stern <stern@rowland.harvard.edu>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrey Konovalov <andreyknvl@google.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
syzbot <syzbot+e74a998ca8f1df9cc332@syzkaller.appspotmail.com>,
LKML <linux-kernel@vger.kernel.org>,
USB list <linux-usb@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: Re: WARNING in pvr2_i2c_core_done
Date: Fri, 27 Sep 2019 10:21:00 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.44L0.1909271015510.1698-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <20190927051042.GA1767219@kroah.com>
On Fri, 27 Sep 2019, Greg Kroah-Hartman wrote:
> > It turns out the reason for this error is simple: The driver
> > unregisters its subdevices in the release handler instead of in the
> > disconnect handler. There probably is documentation about this
> > somewhere, but I don't know exactly where -- maybe Greg remembers.
>
> Nope, I don't remember. It should happen in the disconnect handler, odd
> of it to be in release, but maybe that's the "easiest" way for v4l to
> handle this?
This isn't a question of "easiest". Unregistering child devices in a
release handler is just _wrong_, plain and simple. That's what gives
rise to the
"sysfs group 'power' not found for kobject 'i2c-0'"
warning in the kernel log. The group can't be found because it has
already been removed; it gets destroyed when the parent USB interface
device is unregistered, because unregistering a device also removes
from sysfs everything below that device.
Alan Stern
next prev parent reply other threads:[~2019-09-27 14:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-25 12:59 WARNING in pvr2_i2c_core_done syzbot
2019-09-25 14:10 ` Alan Stern
2019-09-25 15:34 ` Andrey Konovalov
2019-09-26 21:44 ` Alan Stern
2019-09-27 5:10 ` Greg Kroah-Hartman
2019-09-27 14:21 ` Alan Stern [this message]
2020-07-21 11:10 [PATCH] i2c: fix " B K Karthik
2020-07-21 11:20 ` syzbot
2020-07-21 11:55 ` B K Karthik
2020-07-22 3:16 [PATCH v2] i2c: fix " B K Karthik
2020-07-22 4:06 ` syzbot
[not found] ` <20200722091201.2076-1-hdanton@sina.com>
2020-07-22 9:18 ` B K Karthik
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Pine.LNX.4.44L0.1909271015510.1698-100000@iolanthe.rowland.org \
--to=stern@rowland.harvard.edu \
--cc=andreyknvl@google.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=rafael@kernel.org \
--cc=syzbot+e74a998ca8f1df9cc332@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.