Messages in this thread | | | From | Christian Lamparter <> | Subject | Re: [RFC] firmware loader: retry _nowait requests when userhelper is not yet available | Date | Sun, 18 Mar 2012 13:43:40 +0100 |
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On Sunday 18 March 2012 01:29:38 Rafael J. Wysocki wrote: > The patch below (untested) goes slightly into that direction, although not as > far as to modify fw_create_instance(). It does, however, split > _request_firmware() into "prepare", "load" and "cleanup" parts and moves > the usermodehelper check along with the read-locking of umhelper_sem down > to the callers, ie. request_firmware() and request_firmware_work_func(). > > The difference between them is that request_firmware() fails immediately > with a WARN_ON() if it sees usermodehelper_disabled set after acquiring > umhelper_sem, while request_firmware_work_func() waits for > usermodehelper_disabled to be unset, with a timeout (the wait time is > subtracted from the _request_firmware() timeout). The reason why > request_firmware_work_func() does it this way is that it can't wait for > usermodehelper_disabled to be unset with umhelper_sem held and it has to > call _request_firmware() under umhelper_sem (otherwise user space might be > frozen out from under it). > > I'm falling asleep now, but hopefully the patch isn't totally busted. :-) > It should be split into a series of patches, though. I'm happy to report that my test system [with the patch applied] suspended and resumed without any incidents.
Regards, Christian
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