Re: 2.6.25-rc6: CONFIG_USB_PERSIST forced on

From: Alan Stern
Date: Fri Jun 06 2008 - 10:39:31 EST


On Fri, 6 Jun 2008, Pavel Machek wrote:

> Hi!
>
> In 2.6.26-rc5,
>
> -config USB_PERSIST
> - bool "USB device persistence during system suspend (DANGEROUS)"
>
> is now on. Given that it was previously marked "DANGEROUS", that seems
> quite a change to me.

It is. Basically I did it because Linus asked for it -- or at least,
for something like it. He felt that the danger of not having
USB_PERSIST when you need it is worse than the danger of having it when
you don't want it.

> Besides, it seems to have broken usblp hibernation support, and maybe
> other devices that does not have reset_resume() present. (Big thanks
> for Oliver for doing investigation).

URL? It's hard to see how lack of reset-resume support would mess
anything up worse than it would be without USB_PERSIST.

> [Or is it that now USB_PERSIST is conditional on /sys fs setting, so
> while setting it on individual device is dangerous, it is still N by
> default? Changelog does not tell me...?]

USB_PERSIST is (and has always been) conditional on the power/persist
sysfs attribute setting. The difference is that now the setting starts
out as On whereas before it started out as Off, and there no longer is
a Kconfig option to remove USB_PERSIST entirely.

Alan Stern

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