From mboxrd@z Thu Jan 1 00:00:00 1970 From: peterz@infradead.org (Peter Zijlstra) Date: Wed, 25 Feb 2015 16:19:38 +0100 Subject: [PATCH] genirq: better describe IRQF_NO_SUSPEND semantics In-Reply-To: <3607139.EdDhxoz0si@vostro.rjw.lan> References: <1424444026-31231-1-git-send-email-mark.rutland@arm.com> <3607139.EdDhxoz0si@vostro.rjw.lan> Message-ID: <20150225151938.GM5029@twins.programming.kicks-ass.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Feb 24, 2015 at 01:26:05AM +0100, Rafael J. Wysocki wrote: > On Friday, February 20, 2015 02:53:46 PM Mark Rutland wrote: > > The IRQF_NO_SUSPEND flag is intended to be used for interrupts required > > to be enabled during the suspend-resume cycle. This mostly consists of > > IPIs and timer interrupts, potentially including chained irqchip > > interrupts if these are necessary to handle timers or IPIs. If an > > interrupt does not fall into one of the aforementioned categories, > > requesting it with IRQF_NO_SUSPEND is likely incorrect. > > > > Using IRQF_NO_SUSPEND does not guarantee that the interrupt can wake the > > system from a suspended state. For an interrupt to be able to trigger a > > wakeup, it may be necessary to program various components of the system. > > In these cases it is necessary to use {enable,disabled}_irq_wake. > > > > Unfortunately, several drivers assume that IRQF_NO_SUSPEND ensures that > > an IRQ can wake up the system, and the documentation can be read > > ambiguously w.r.t. this property. > > > > This patch updates the documentation regarding IRQF_NO_SUSPEND to make > > this caveat explicit, hopefully making future misuse rarer. Cleanup of > > existing misuse will occur as part of later patch series. > > > > Cc: Boris Brezillon > > Cc: Ian Campbell > > Cc: Jonathan Corbet > > Cc: Peter Zijlstra > > Cc: Rafael J. Wysocki > > Cc: Thomas Gleixner > > Signed-off-by: Mark Rutland > > Applied to linux-pm.git/linux-next, thanks! > > Peter, please let me know if you don't want this to go it. No seems fine, Thanks! Acked-by: Peter Zijlstra (Intel)