Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030362AbbDWRuE (ORCPT ); Thu, 23 Apr 2015 13:50:04 -0400 Received: from mail-oi0-f44.google.com ([209.85.218.44]:35566 "EHLO mail-oi0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966432AbbDWRuA (ORCPT ); Thu, 23 Apr 2015 13:50:00 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Thu, 23 Apr 2015 19:49:59 +0200 X-Google-Sender-Auth: sJwgQ3_6MoDbjq0hj759rsdqXrk Message-ID: Subject: Re: [PATCH/RFC 00/03] irqchip: renesas-irqc: Fine grained Runtime PM support From: Geert Uytterhoeven To: Alan Stern Cc: Magnus Damm , Linux-sh list , Jason Cooper , Geert Uytterhoeven , Linux PM list , "linux-kernel@vger.kernel.org" , Simon Horman , Thomas Gleixner Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1727 Lines: 40 On Thu, Apr 23, 2015 at 4:44 PM, Alan Stern wrote: > On Thu, 23 Apr 2015, Geert Uytterhoeven wrote: >> >> I'm afraid you can't call pm_runtime_get_sync() from these methods, as >> >> they may be called from interrupt context. >> > >> > Ouch. I know the clock framework has prepare/enable separated with >> > context, but with the irqchip callbacks I suppose no such separation >> >> It's not the clock operations, but the pm_runtime operations that cannot be >> called from interrupt context. > > In fact the pm_runtime operations _can_ be called from interrupt > context, provided the driver has first invoked pm_runtime_irq_safe(). > Of course, this requires that none of the runtime-PM callback routines > ever sleep or perform a blocking operation. > > This is all explained in Documentation/power/runtime_pm.txt (search for > "irq_safe"). Perhaps that can help. We'll have to give it a try... I've always found this a bit strange when PM Domains are involved: pm_runtime_irq_safe(dev) applies to device dev, while the actual callbacks belong to the PM Domain code (the device's driver doesn't have any). Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/