Messages in this thread | | | Subject | Re: [RFC][PATCH] PM: Introduce new top level suspend and hibernation callbacks (rev. 6) | From | Nigel Cunningham <> | Date | Wed, 02 Apr 2008 06:34:27 +1100 |
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Hi.
On Tue, 2008-04-01 at 10:31 -0400, Alan Stern wrote: > On Tue, 1 Apr 2008, Benjamin Herrenschmidt wrote: > > > On Tue, 2008-04-01 at 19:15 +1100, Nigel Cunningham wrote: > > > > + * However, drivers may NOT assume anything about the availability of the > > > > + * user space at that time and it is not correct to request firmware from > > > > + * within @prepare() (it's too late to do that). > > > > > > That doesn't sound good. It would be good to be able to get drivers to > > > request firmware early in the process. > > > > Agreed. Prepare() should still allow request_firmware and full userspace > > communication / helper usage. > > Pepare() is called after userspace has been frozen. (Of course, once > the freezer goes away this won't matter any more.) > > There is a separate notifier chain which drivers can subscribe to; > notifications about impending sleeps are sent out while userspace is > still alive. Drivers can use that for request_firmware, memory > allocation, and other things.
Then that should be mentioned here so that drivers authors can know that it is possible to request firmware, allocate memory and so on at a stage when you can still rely on userspace being alive.
Regards,
Nigel
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