On Saturday, July 26, 2014 01:49:17 PM Rafael J. Wysocki wrote: > On Saturday, July 26, 2014 12:25:29 AM Rafael J. Wysocki wrote: > > On Friday, July 25, 2014 11:00:12 PM Thomas Gleixner wrote: > > > On Fri, 25 Jul 2014, Rafael J. Wysocki wrote: > > > > On Friday, July 25, 2014 03:25:41 PM Peter Zijlstra wrote: > > > > > OK, so Rafael said there's devices that keep on raising their > > > > > interrupt > > > > > until they get attention. Ideally this won't happen because the device > > > > > is suspended etc.. But I'm sure there's some broken piece of hardware > > > > > out there that'll make it go boom. > > > > > > > > So here's an idea. > > > > > > > > What about returning IRQ_NONE rather than IRQ_HANDLED for "suspended" > > > > interrupts (after all, that's what a sane driver would do for a > > > > suspended device I suppose)? > > > > > > > > If the line is really shared and the interrupt is taken care of by > > > > the other guy sharing the line, we'll be all fine. > > > > > > > > If that is not the case, on the other hand, and something's really > > > > broken, we'll end up disabling the interrupt and marking it as > > > > IRQS_SPURIOUS_DISABLED (if I understand things correctly). > > > > > > We should not wait 100k unhandled interrupts in that case. We know > > > already at the first unhandled interrupt that the shit hit the fan. > > > > The first one may be a bus glitch or some such. Also I guess we still need > > to > > allow the legitimate "no suspend" guy to handle his interrupts until it gets > > too worse. > > > > Also does it really hurt to rely on the generic mechanism here? We regard > > it as fine at all other times after all. > > > > > I'll have a deeper look how we can sanitize the whole wake/no_suspend > > > logic vs. shared interrupts. > > One more idea, on top of the prototype patch that I posted > (https://patchwork.kernel.org/patch/4625921/). > > The problem with enable_irq_wake() is that it only takes one argument, so > if that's a shared interrupt, we can't really say which irqaction is supposed > to handle wakeup interrupts should they occur. > > To address this we can introduce enable_device_irq_wake() that will take > an additional dev_id argument (that must be the one passed to request_irq() or > the operation will fail) that can be used to identify the irqaction for > handling the wakeup interrupts. It can work by setting IRQF_NO_SUSPEND > for the irqaction in question and doing the rest along the lines of > irq_set_irq_wake(irq, 1). disable_device_irq_wake() will then clear > IRQF_NO_SUSPEND (it also has to be passed the dev_id argument). > > If we have that, the guys who need to set up device interrupts (ie. interrupts > normally used for signaling input events etc) for system wakeup will need to > use enable_device_irq_wake() and that should just work.
That could be used to address the PCIe PME interrupt wakeup and gpio-keys driver wakeup in the same way at least. Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
