linux-kernel - Re: [PATCH 1/1] driver core: disable device's runtime pm during shutdown

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.44L0.1112051100150.5138-100000@iolanthe.rowland.org>
Date:	Mon, 5 Dec 2011 11:02:38 -0500 (EST)
From:	Alan Stern <stern@...land.harvard.edu>
To:	Ming Lei <tom.leiming@...il.com>
cc:	Chen Peter-B29397 <B29397@...escale.com>,
	NeilBrown <neilb@...e.de>, "Rafael J. Wysocki" <rjw@...k.pl>,
	Greg KH <greg@...ah.com>, "gregkh@...e.de" <gregkh@...e.de>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	"hzpeterchen@...il.com" <hzpeterchen@...il.com>,
	Igor Grinberg <grinberg@...pulab.co.il>
Subject: Re: [PATCH 1/1] driver core: disable device's runtime pm during
 shutdown

On Mon, 5 Dec 2011, Ming Lei wrote:

> Sorry, the above is line wrapped badly, see the below:
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index d8b3d89..96b266c 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -1743,8 +1743,9 @@ void device_shutdown(void)
>  		 */
>  		list_del_init(&dev->kobj.entry);
>  		spin_unlock(&devices_kset->list_lock);
> -		/* Disable all device's runtime power management */
> -		pm_runtime_disable(dev);
> +
> +		/* put device into active state and forbit runtime pm */
> +		pm_runtime_forbid(dev);
> 
>  		if (dev->bus && dev->bus->shutdown) {
>  			dev_dbg(dev, "shutdown\n");

We don't want to put devices into the active state when it's not 
necessary.  A better approach would be:

		/* Don't allow any more runtime suspends */
		pm_runtime_get_noresume(dev);
		pm_runtime_barrier(dev);

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/