From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754787AbaK0Jzz (ORCPT ); Thu, 27 Nov 2014 04:55:55 -0500 Received: from mail-ie0-f170.google.com ([209.85.223.170]:51889 "EHLO mail-ie0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752749AbaK0Jzv (ORCPT ); Thu, 27 Nov 2014 04:55:51 -0500 Date: Thu, 27 Nov 2014 09:55:44 +0000 From: Lee Jones To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, jason@lakedaemon.net, linux-kernel@vger.kernel.org, tglx@linutronix.de, kernel@stlinux.com Subject: Re: [PATCH v2 2/8] irqchip: Supply new driver for STi based devices Message-ID: <20141127095544.GF4628@x1> References: <1416932705-16880-1-git-send-email-lee.jones@linaro.org> <35179358.tOpRGufXmc@wuerfel> <20141127092901.GE4628@x1> <2111250.BPZOtBCtcF@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2111250.BPZOtBCtcF@wuerfel> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 27 Nov 2014, Arnd Bergmann wrote: > On Thursday 27 November 2014 09:29:01 Lee Jones wrote: > > On Thu, 27 Nov 2014, Arnd Bergmann wrote: > > > On Thursday 27 November 2014 09:02:55 Lee Jones wrote: > > > > On Tue, 25 Nov 2014, Arnd Bergmann wrote: > > > > > > > > > On Tuesday 25 November 2014 16:24:59 Lee Jones wrote: > > > > > > > > > > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig > > > > > > index b21f12f..e502f15 100644 > > > > > > --- a/drivers/irqchip/Kconfig > > > > > > +++ b/drivers/irqchip/Kconfig > > > > > > @@ -93,6 +93,13 @@ config RENESAS_IRQC > > > > > > bool > > > > > > select IRQ_DOMAIN > > > > > > > > > > > > +config ST_IRQCHIP > > > > > > + bool > > > > > > + select REGMAP > > > > > > + select MFD_SYSCON > > > > > > + help > > > > > > + Enables SysCfg Controlled IRQs on STi based platforms. > > > > > > + > > > > > > > > > > I'm confused by the purpose of this code. It's apparently a driver > > > > > in drivers/irqchip, the Kconfig symbol contains the string IRQCHIP, > > > > > yet it doesn't actually register an irq_chip. > > > > > > > > > > Also, the name is a bit too generic, ST has lots of different irqchips, > > > > > and this apparently isn't even one of them > > > > > > > > Hmm... now you're going to ask me to remember who I had the > > > > conversation with that alluded to this as the best location for this > > > > driver. Unfortunately, I cannot. Can you think of a better place to > > > > put it then? > > > > > > I suspect it's in the right place but should actually be an irqchip > > > driver. I'm having trouble understanding what this code actually does, > > > can you you explain the functionality in more detail so we can figure > > > out what to do with it? > > > > In the simplest terms it's an IRQ unmasker. A9 Core IRQs are disabled > > on boot; PMU, CTI (CoreSight), PL310_L2 and EXT. In order for you to > > make use of them they need to be unmasked in SYSCFG. > > So you just apply static configuration once, or are there reasons why you > would mask the interrupts again later? > > If it's all static, why doesn't the boot loader unmask all interrupts before > starting the kernel? We'd like to configure them at boot-time, via DT. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog