Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [RFC PATCH 0/3] genirq: mixing IRQF_NO_SUSPEND and wakeup sources on shared IRQs | Date | Thu, 26 Feb 2015 22:55:50 +0100 |
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On Thursday, February 26, 2015 07:17:24 PM Boris Brezillon wrote: > On Thu, 26 Feb 2015 19:17:03 +0100 > "Rafael J. Wysocki" <rjw@rjwysocki.net> wrote: > > > On Thursday, February 26, 2015 04:47:24 PM Boris Brezillon wrote: > > > On Thu, 26 Feb 2015 16:44:16 +0100 > > > "Rafael J. Wysocki" <rjw@rjwysocki.net> wrote: > > [...] > > > > > > > > > But it is still a bit risky. Namely, if the driver in question is sufficiently > > > > broken (eg. it may not suspend the device and rely on the fact that its interrupt > > > > handler will be run just because it is sharing a "no suspend" IRQ), we may get > > > > an interrupt storm. > > > > > > > > Isn't that a problem? > > > > > > For me no (I'll fix all the drivers to handle wakeup, and they are all > > > already masking interrupts coming from their side in the suspend > > > callback). > > > I can't talk for other people though. > > > The only problem I see here is that you're not informing people that > > > they are erroneously mixing IRQF_NO_SUSPEND and !IRQF_NO_SUSPEND anymore > > > (you removed the warning backtrace). > > > Moreover, you are replacing their handler by a stub when entering > > > suspend, so they might end-up receiving spurious interrupts when > > > suspended without knowing why ? > > > > > > How about checking if the number of actions registered with > > > IRQF_NO_SUSPEND + those registered with IRQF_COND_SUSPEND (or another > > > flag stating that the handler can safely be called in suspended state > > > even if it didn't ask for NO_SUSPEND) are equal to the total number of > > > registered actions, and complain if it's not the case. > > > > The same idea I had while talking to Peter over IRC. So the patch below > > implements that. > > Yep, that's what I had in mind.
OK, thanks.
I'll submit it formally, then.
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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