From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.187]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id BCC8D1A0679 for ; Mon, 12 Oct 2015 21:30:27 +1100 (AEDT) From: Arnd Bergmann To: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linuxppc-dev@ozlabs.org, thuth@redhat.com Subject: Re: [PATCH 1/6] powerpc/kconfig: Move NR_IRQS into "Kernel Options" Date: Mon, 12 Oct 2015 12:30:18 +0200 Message-ID: <7516455.YEROTAngT1@wuerfel> In-Reply-To: <1444644025.31951.1.camel@ellerman.id.au> References: <1444338557-14988-1-git-send-email-mpe@ellerman.id.au> <7826129.RXlL8kStvO@wuerfel> <1444644025.31951.1.camel@ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Monday 12 October 2015 21:00:25 Michael Ellerman wrote: > On Thu, 2015-10-08 at 23:30 +0200, Arnd Bergmann wrote: > > On Friday 09 October 2015 08:09:12 Michael Ellerman wrote: > > > Currently the NR_IRQS option sits at the top level, which is ugly in > > > menuconfig. It's not something users will commonly need to worry about > > > so move it into "Kernel Options". > > > > Is this option actually still meaningful at all, when you select CONFIG_SPARSE_IRQ > > unconditionally? > > It's still used for #define NR_IRQS, which is still used by the generic irq > code and also some drivers. Drivers shouldn't use it, and I don't see any driver using it that can be enabled on powerpc. The question is rather whether you have any devices on powerpc that get a hardwired IRQ number from a statically defined platform device rather from DT. If there are any ISA devices, the driver might try to use an interrupt number that is hardcoded in the driver as a number from 0 to 15. I guess that could happen on old CHRP or 6xx machines. > So we need some value for that, whether it needs to be user defined or if we > could just pick a value I'm not sure. x86 seem to just define it based on > NR_CPUs and some other factors. What happens if you set it to 16? Arnd