From: Alan Stern <stern@rowland.harvard.edu>
To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ming Lei <tom.leiming@gmail.com>, <linux-pci@vger.kernel.org>,
USB list <linux-usb@vger.kernel.org>,
Linux PM list <linux-pm@vger.kernel.org>
Subject: Re: Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...)
Date: Sat, 4 Aug 2012 18:13:11 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.44L0.1208041806490.23711-100000@netrider.rowland.org> (raw)
In-Reply-To: <201208042315.44031.rjw@sisk.pl>
On Sat, 4 Aug 2012, Rafael J. Wysocki wrote:
> On Saturday, August 04, 2012, Alan Stern wrote:
> > On Sat, 4 Aug 2012, Rafael J. Wysocki wrote:
> >
> > > > That wasn't what he meant. What if the code needs to run in the _same_
> > > > context as the caller? For example, with a spinlock held.
> > >
> > > I see. I think it wouldn't be unreasonable to require that func should take
> > > all of the necessary locks by itself.
> >
> > But then if func was called directly, because the device was at full
> > power, it would deadlock trying to acquire a lock the caller already
> > holds.
>
> I wonder why the caller may want to take any locks beforehand?
Who knows? :-)
The best answer may be for the caller not to hold any locks. In the
runtime-PM document's example driver, the lock would be dropped before
the resume-and-call.
> > Do you have any better suggestions?
>
> Hmm. What about pm_runtime_get_and_call(dev, func_sync, func_async), where
> func_sync() is to be called if the device is already active and func_async()
> is to be called if it has to be resumed from the workqueue?
That's a little better but not much. It would require storing two
function pointers in the dev->power structure.
Alan Stern
next prev parent reply other threads:[~2012-08-04 22:13 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.LNX.4.44L0.1207241312050.1164-100000@iolanthe.rowland.org>
[not found] ` <87r4s0opck.fsf@nemi.mork.no>
2012-07-25 4:08 ` bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure Bjørn Mork
2012-07-25 4:34 ` Huang Ying
2012-07-25 9:58 ` Bjørn Mork
2012-07-25 13:30 ` huang ying
2012-07-25 13:58 ` Bjørn Mork
2012-07-25 18:56 ` Rafael J. Wysocki
2012-07-25 20:02 ` Rafael J. Wysocki
2012-07-25 22:36 ` Bjørn Mork
2012-07-26 2:38 ` Huang Ying
2012-07-26 2:38 ` Huang Ying
2012-07-26 8:54 ` Huang Ying
2012-07-26 10:35 ` Bjørn Mork
2012-07-26 11:02 ` Bjørn Mork
2012-07-26 12:04 ` Bjørn Mork
2012-07-26 15:03 ` Alan Stern
2012-07-26 16:24 ` Bjørn Mork
2012-07-27 5:35 ` Huang Ying
2012-07-27 9:11 ` Bjørn Mork
2012-07-30 3:15 ` Huang Ying
2012-07-30 8:08 ` Bjørn Mork
2012-07-30 13:31 ` huang ying
2012-07-30 16:57 ` Bjørn Mork
2012-07-31 0:22 ` Huang Ying
2012-07-30 14:19 ` Alan Stern
2012-07-31 0:24 ` Huang Ying
2012-07-31 3:18 ` Huang Ying
2012-07-31 17:07 ` Alan Stern
2012-07-27 15:03 ` Alan Stern
2012-07-27 19:11 ` Rafael J. Wysocki
2012-07-27 19:39 ` Alan Stern
2012-07-27 19:54 ` Rafael J. Wysocki
2012-07-28 16:12 ` Alan Stern
2012-07-28 20:26 ` Rafael J. Wysocki
2012-07-28 21:12 ` Alan Stern
2012-07-29 13:55 ` Rafael J. Wysocki
2012-07-29 14:55 ` Alan Stern
2012-07-29 19:18 ` Rafael J. Wysocki
2012-07-31 20:31 ` Do we need asynchronous pm_runtime_get()? (was: Re: bisected regression ...) Rafael J. Wysocki
2012-07-31 21:05 ` Alan Stern
2012-07-31 21:34 ` Rafael J. Wysocki
2012-07-31 21:49 ` Rafael J. Wysocki
2012-08-01 14:36 ` Alan Stern
2012-08-01 21:24 ` Rafael J. Wysocki
2012-08-02 20:16 ` Alan Stern
2012-08-02 21:26 ` Rafael J. Wysocki
2012-08-03 2:20 ` Alan Stern
2012-08-03 3:37 ` Ming Lei
2012-08-03 14:28 ` Alan Stern
2012-08-04 19:47 ` Rafael J. Wysocki
2012-08-04 20:25 ` Alan Stern
2012-08-04 20:48 ` Rafael J. Wysocki
2012-08-04 20:48 ` Alan Stern
2012-08-04 21:15 ` Rafael J. Wysocki
2012-08-04 22:13 ` Alan Stern [this message]
2012-08-05 15:26 ` Rafael J. Wysocki
2012-08-06 13:30 ` Ming Lei
2012-08-06 14:47 ` Alan Stern
2012-08-07 1:35 ` Ming Lei
2012-08-07 11:23 ` Rafael J. Wysocki
2012-08-07 15:14 ` Ming Lei
2012-08-07 15:42 ` Alan Stern
2012-08-07 16:30 ` Ming Lei
2012-08-07 20:57 ` Rafael J. Wysocki
2012-08-07 20:45 ` Rafael J. Wysocki
2012-08-08 2:02 ` Ming Lei
2012-08-08 18:42 ` Alan Stern
2012-08-08 20:16 ` Rafael J. Wysocki
2012-08-09 5:55 ` Ming Lei
2012-08-09 10:46 ` Rafael J. Wysocki
2012-08-09 10:55 ` Ming Lei
2012-08-09 19:41 ` Rafael J. Wysocki
2012-08-10 3:19 ` Ming Lei
2012-08-10 20:29 ` Rafael J. Wysocki
2012-08-08 22:27 ` Rafael J. Wysocki
2012-08-06 15:48 ` Alan Stern
2012-08-06 20:30 ` Rafael J. Wysocki
2012-08-07 12:28 ` Rafael J. Wysocki
2012-08-07 17:15 ` Alan Stern
2012-08-07 21:31 ` Rafael J. Wysocki
2012-08-03 14:05 ` Alan Stern
2012-08-04 20:08 ` Rafael J. Wysocki
2012-08-04 20:42 ` Alan Stern
2012-08-04 20:59 ` Rafael J. Wysocki
2012-08-04 19:35 ` Rafael J. Wysocki
2012-07-29 20:12 ` bisected regression, v3.5 -> next-20120724: PCI PM causes USB hotplug failure Jassi Brar
2012-07-29 21:44 ` Alan Stern
2012-07-25 19:51 ` [PATCH] PCI / PM: Fix messages printed by acpi_pci_set_power_state() Rafael J. Wysocki
2012-07-25 20:02 ` Alan Stern
2012-07-25 20:48 ` [PATCH][update] " Rafael J. Wysocki
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.4.44L0.1208041806490.23711-100000@netrider.rowland.org \
--to=stern@rowland.harvard.edu \
--cc=linux-pci@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=rjw@sisk.pl \
--cc=tom.leiming@gmail.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.