On Wednesday, February 11, 2015 11:15:17 AM Mark Rutland wrote: > On Wed, Feb 11, 2015 at 09:11:59AM +0000, Peter Zijlstra wrote: > > On Tue, Feb 10, 2015 at 08:48:36PM +0000, Mark Rutland wrote: > > > From f390ccbb31f06efee49b4469943c8d85d963bfb5 Mon Sep 17 00:00:00 2001 > > > From: Mark Rutland <mark.rutl...@arm.com> > > > Date: Tue, 10 Feb 2015 20:14:33 +0000 > > > Subject: [PATCH] genirq: allow mixed IRQF_NO_SUSPEND requests > > > > > > In some cases a physical IRQ line may be shared between devices from > > > which we expect interrupts during suspend (e.g. timers) and those we do > > > not (e.g. anything we cut the power to). Where a driver did not request > > > the interrupt with IRQF_NO_SUSPEND, it's unlikely that it can handle > > > being called during suspend, and it may bring down the system. > > > > > > This patch adds logic to automatically mark the irqactions for these > > > potentially unsafe handlers as disabled during suspend, leaving actions > > > with IRQF_NO_SUSPEND enabled. If an interrupt is raised on a shared line > > > during suspend, only the handlers requested with IRQF_NO_SUSPEND will be > > > called. The handlers requested without IRQF_NO_SUSPEND will be skipped > > > as if they had immediately returned IRQF_NONE. > > > > > > Cc: Boris Brezillon <boris.brezil...@free-electrons.com> > > > Cc: Jason Cooper <ja...@lakedaemon.net> > > > Cc: Nicolas Ferre <nicolas.fe...@atmel.com> > > > Cc: Peter Zijlstra <pet...@infradead.org> > > > Cc: Rafael J. Wysocki <rafael.j.wyso...@intel.com> > > > Cc: Thomas Gleixner <t...@linutronix.de> > > > Signed-off-by: Mark Rutland <mark.rutl...@arm.com> > > > > Aw gawd.. not that again. > > I agree this isn't pretty, but at least it doesn't require the HW > description to know about Linux internals, and it can work for !DT > systems. > > I'm really not happy with placing Linux implementation details into > DTBs. > > > So Rafael and tglx went over this a few months ago I think: > > > > lkml.kernel.org/r/26580319.ozp7jvj...@vostro.rjw.lan > > > > is the last series I could find. Maybe Rafael can summarize? > > I can't get at any commentary from that link, unfortunately. > > Rafael?
Well, the commentary is not there, because both I and Thomas implicitly agreed on one thing: We cannot add any suspend-related checks to the interrupt handling hot path, because that will affect everyone including people who don't use suspend at all and who *really* care about interrupt handling performance. 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/
