From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: "Ohad Ben-Cohen" <ohad@wizery.com>
Cc: Alan Stern <stern@rowland.harvard.edu>,
linux-pm@lists.linux-foundation.org,
Johannes Berg <johannes@sipsolutions.net>,
linux-wireless@vger.kernel.org, linux-mmc@vger.kernel.org,
Ido Yariv <ido@wizery.com>,
Kevin Hilman <khilman@deeprootsystems.com>
Subject: Re: [linux-pm] subtle pm_runtime_put_sync race and sdio functions
Date: Tue, 28 Dec 2010 20:21:31 +0100 [thread overview]
Message-ID: <201012282021.31695.rjw@sisk.pl> (raw)
In-Reply-To: <AANLkTimHHN+GesyhR6Jjnm771XLhn=inn=vrSk=mT6Mh@mail.gmail.com>
On Tuesday, December 28, 2010, Ohad Ben-Cohen wrote:
> On Sun, Dec 26, 2010 at 8:35 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > On Sunday, December 26, 2010, Ohad Ben-Cohen wrote:
> >> On Sun, Dec 26, 2010 at 1:45 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> > Why does the driver need the device to be reset even though it hasn't
> >> > been suspeneded yet?
> >>
> >> Because it is asked to stop the hardware by mac80211.
> >
> > So I guess the mac80211 layer should ask it to start it again.
>
> It does...
>
> And at this point the driver will try to boot a new firmware, but it
> will only succeed if the device was indeed powered off. If it wasn't
> (system suspend was cancelled before the host controller suspended),
> the driver will fail to resume the device (because it can't reset it).
It looks like you could simply do a power down-power up cycle before trying to
load new firmware, just in case. I guess that's suboptimal for some reason?
> We can change man80211 to let us know the system is suspending, and
> then we will power down the device directly. Or we can use something
> like your "runtime only" proposal, and then pm_runtime_put_sync() will
> just work for us regardless of the system state.
The pm_runtime_put_sync() is irrelevant at this point IMHO. First, we should
figure out what needs to be done at the low level and _then_ think how to
code it. From that we'll learn if you _really_ need anything new from the PM
core, but quite frankly I seriously doubt it right now.
> But that will not solve the /sys/devices/.../power/control problem.
> For that we will either have always to bypass runtime PM, or introduce
> something like "always auto"...
Please pretend that the runtime PM framework doesn't exist for a while. How
would you design things in that case?
Rafael
next prev parent reply other threads:[~2010-12-28 19:22 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <AANLkTikJr+0kVPE4aSwPjZWRfA3gRSNgGwzQdSwRpo_5@mail.gmail.com>
[not found] ` <Pine.LNX.4.44L0.1012110937100.10743-100000@netrider.rowland.org>
[not found] ` <AANLkTi=32bqipN5U00La-B7JSgTC1bHgMev=xUSF6kRN@mail.gmail.com>
[not found] ` <201012181607.26628.rjw@sisk.pl>
2010-12-18 16:00 ` [linux-pm] subtle pm_runtime_put_sync race and sdio functions Ohad Ben-Cohen
2010-12-18 16:40 ` Johannes Berg
2010-12-18 19:08 ` Ohad Ben-Cohen
2010-12-18 21:30 ` Alan Stern
2010-12-18 22:57 ` Rafael J. Wysocki
2010-12-18 22:52 ` Rafael J. Wysocki
2010-12-18 21:29 ` Alan Stern
2010-12-18 22:50 ` Rafael J. Wysocki
2010-12-18 22:47 ` Rafael J. Wysocki
2010-12-19 7:48 ` Ohad Ben-Cohen
2010-12-19 10:22 ` Rafael J. Wysocki
2010-12-20 3:37 ` Alan Stern
2010-12-20 21:17 ` Rafael J. Wysocki
2010-12-21 0:57 ` Alan Stern
2010-12-21 21:31 ` Rafael J. Wysocki
2010-12-22 1:42 ` Alan Stern
2010-12-22 12:29 ` Rafael J. Wysocki
2011-01-26 23:28 ` Kevin Hilman
2011-01-27 18:13 ` Alan Stern
2011-01-27 19:22 ` Kevin Hilman
2011-01-27 19:49 ` Alan Stern
2011-01-27 20:15 ` Kevin Hilman
2011-01-27 22:18 ` Vitaly Wool
2011-01-27 23:21 ` Rafael J. Wysocki
2011-01-27 23:49 ` Kevin Hilman
2011-01-27 23:11 ` Rafael J. Wysocki
2011-01-27 18:20 ` Vitaly Wool
2011-01-27 18:54 ` Kevin Hilman
2010-12-21 22:23 ` Kevin Hilman
2010-12-22 1:48 ` Alan Stern
2010-12-23 7:51 ` Ohad Ben-Cohen
2010-12-23 16:03 ` Alan Stern
2010-12-25 7:34 ` Ohad Ben-Cohen
2010-12-25 16:21 ` Alan Stern
2010-12-25 20:58 ` Ohad Ben-Cohen
2010-12-25 21:50 ` Vitaly Wool
2010-12-26 5:27 ` Ohad Ben-Cohen
2010-12-25 21:54 ` Vitaly Wool
2010-12-26 2:48 ` Alan Stern
2010-12-26 5:55 ` Ohad Ben-Cohen
2010-12-26 11:45 ` Rafael J. Wysocki
2010-12-26 12:43 ` Ohad Ben-Cohen
2010-12-26 18:35 ` Rafael J. Wysocki
2010-12-28 19:11 ` Ohad Ben-Cohen
2010-12-28 19:21 ` Rafael J. Wysocki [this message]
2010-12-28 19:34 ` Ohad Ben-Cohen
2010-12-28 20:36 ` Rafael J. Wysocki
2010-12-26 14:53 ` Ohad Ben-Cohen
2010-12-26 18:37 ` Rafael J. Wysocki
2010-12-28 19:15 ` Ohad Ben-Cohen
2010-12-28 20:04 ` Rafael J. Wysocki
2010-12-28 20:41 ` Ohad Ben-Cohen
2010-12-26 17:00 ` Alan Stern
2010-12-28 19:04 ` Ohad Ben-Cohen
2010-12-28 21:46 ` Alan Stern
2010-12-29 6:34 ` Ohad Ben-Cohen
2010-12-30 4:25 ` Alan Stern
2010-12-29 8:01 ` Ohad Ben-Cohen
2010-12-30 4:30 ` Alan Stern
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