From: Oliver Neukum <oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org>
To: Hayes Wang <hayeswang-Rasf1IRRPZFBDgjK7y7TUQ@public.gmane.org>
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
nic_swsd-Rasf1IRRPZFBDgjK7y7TUQ@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH net] r8152: use cancel_delayed_work for runtime suspend
Date: Sat, 18 Oct 2014 21:48:19 +0200 [thread overview]
Message-ID: <1413661699.19391.2.camel@linux-0dmf.site> (raw)
In-Reply-To: <1394712342-15778-64-Taiwan-albertk-Rasf1IRRPZFBDgjK7y7TUQ@public.gmane.org>
On Fri, 2014-10-17 at 13:55 +0800, Hayes Wang wrote:
> It would cause dead lock for runtime suspend, when the workqueue
> is running and runtime suspend occurs before the workqueue wakes
> up the device. The rtl8152_suspend() waits the workqueue to finish
> because of calling cancel_delayed_work_sync(). The workqueue waits
> the suspend function to finish for waking up the device because of
> calling usb_autopm_get_interface().
The diagnosis is good, the fix is not good. It opens a race
during which the queued work can touch a suspended device.
Regards
Oliver
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2014-10-18 19:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-17 5:55 [PATCH net] r8152: use cancel_delayed_work for runtime suspend Hayes Wang
2014-10-17 7:42 ` Bjørn Mork
2014-10-17 8:55 ` [PATCH net] r8152: return -EBUSY " Hayes Wang
2014-10-18 3:46 ` David Miller
[not found] ` <1394712342-15778-64-Taiwan-albertk-Rasf1IRRPZFBDgjK7y7TUQ@public.gmane.org>
2014-10-18 19:48 ` Oliver Neukum [this message]
[not found] ` <1413661699.19391.2.camel-AfvqVibwNMkMNNZnWhT/Jw@public.gmane.org>
2014-10-20 2:19 ` [PATCH net] r8152: use cancel_delayed_work " Hayes Wang
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=1413661699.19391.2.camel@linux-0dmf.site \
--to=oliver-gvhc2dphhpqdnm+yrofe0a@public.gmane.org \
--cc=hayeswang-Rasf1IRRPZFBDgjK7y7TUQ@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=nic_swsd-Rasf1IRRPZFBDgjK7y7TUQ@public.gmane.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).