Messages in this thread | | | From | Oliver Neukum <> | Subject | Re: [PATCH 5/5] opticon: Fix resume logic | Date | Wed, 7 Oct 2009 18:01:58 +0200 |
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Am Mittwoch, 7. Oktober 2009 17:56:02 schrieb Johan Hovold: > On Tue, Oct 06, 2009 at 11:23:31PM +0100, Alan Cox wrote: > > On Tue, 6 Oct 2009 23:12:17 +0200 > > > > Oliver Neukum <oliver@neukum.org> wrote: > > > Am Dienstag, 6. Oktober 2009 17:06:57 schrieb Alan Cox: > > > > Opticon now takes the right mutex to check the port status but the > > > > status check is done wrongly for the modern serial code, so fix it. > > > > > > As Alan Stern noticed, it seems like we have an ab-ba deadlock here > > > between open and resume regarding pm_mutex and port->mutex. > > > > Oh well I guess someone with hardware will have to fix that. > > > > Do we actually need a separate pm_mutex anyway ? > > The pm_mutex is actually not aquired during open (and Alan Stern just > confirmed that), so there is no dead-lock with port->mutex.
This is currently true, but will no longer be true if autosuspend is implemented for this driver.
Regards Oliver
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