On Feb 02 Alan Stern wrote: > On Sat, 2 Feb 2013, Stefan Richter wrote: > > > On Feb 01 Mark Einon wrote: > > > On 1 February 2013 21:09, Peter Hurley <[email protected]> wrote: > > > >>>> On Jan 29 Alan Stern wrote: > > > >>>>> Why does the pci_suspend routine call free_irq() at all? As far as > > > >>>>> I > > > >>>>> know, it's not supposed to do that. Won't the device continue to > > > >>>>> use > > > >>>>> the same IRQ after it is resumed? > > > > As far as I can tell, it happened to be done that way as a side effect of > > how the probe() and resume() methods share code. It has remained like > > this since the initial implementation: > > http://git.kernel.org/linus/2aef469a35a2 > > At one point, quite a few years ago, Linus complained about drivers the > release IRQs during suspend only to reacquire them during resume. A > little refactoring should be able to separate out resource > acquisition/release (done only during probe and remove) from activation > and shutdown (also done during resume and suspend). > > > Still, at this point I would like to learn whether .suspend() followed > > by .remove() is a valid order of sequence which drivers must support > > before I prepare myself to get comfortable with a refactoring of > > firewire-ohci's .probe()/.resume()/suspend()/remove(). Obviously, so far > > my assumption was that a successful .suspend() can only ever be followed > > by .resume(). > > It depends on the subsystem. Some subsystems do have suspend -> remove > transitions and others don't. In general, it's a good idea for drivers > to be prepared for removal while the system is asleep. Presumably any > hot-unpluggable bus (which includes most of the important buses these > days) would have to support it.
OK, thank you. In this case we are of course dealing with the pci subsystem (and with PCI/ CardBus/ PCI Express/ ExpressCard attached hardware). Maybe I should have addressed my question to linux-pci instead of linux-pm; however, if this is the general expectation, then I too prefer firewire-ohci to be able to handle it even if the pci subsystem wouldn't require it presently (which now sounds unlikely). -- Stefan Richter -=====-===-= --=- ---=- http://arcgraph.de/sr/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
