From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4D377CE3.6000608@mentor.com> Date: Wed, 19 Jan 2011 18:08:03 -0600 From: Meador Inge MIME-Version: 1.0 To: Yoder Stuart-B08248 Subject: Re: [PATCH 1/2] powerpc: document the MPIC device tree binding References: <4D34E448.8000902@mentor.com> <9F6FE96B71CF29479FF1CDC8046E150306BF11@039-SN1MPN1-004.039d.mgd.msft.net> In-Reply-To: <9F6FE96B71CF29479FF1CDC8046E150306BF11@039-SN1MPN1-004.039d.mgd.msft.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: "Blanchard, Hollis" , Wood Scott-B07421 , "devicetree-discuss@lists.ozlabs.org" , "linuxppc-dev@lists.ozlabs.org" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 01/19/2011 04:14 PM, Yoder Stuart-B08248 wrote: > >> +** Optional properties: >> + >> + - no-reset : The presence of this property indicates that the MPIC >> + should not be reset during runtime initialization. >> + - protected-sources : Specifies a list of interrupt sources that are >> + not >> + available for use and whose corresponding >> + vectors >> + should not be initialized. A typical use case >> + for >> + this property is in AMP systems where multiple >> + independent operating systems need to share >> + the MPIC >> + without clobbering each other. > > Is "protected-sources" really needed for AMP systems to > tell the OSes not to clobber each other? Won't each > OS be given a device tree with only its interrupt > sources? ...so you know what you are allowed to touch. This was discussed a little bit already [1, 2]. The MPIC driver currently initializes the VECPRI register for all interrupt sources, which can lead to the aforementioned clobbering. -- Meador Inge | meador_inge AT mentor.com Mentor Embedded | http://www.mentor.com/embedded-software [1] http://lists.ozlabs.org/pipermail/devicetree-discuss/2010-December/003850.html [2] http://lists.ozlabs.org/pipermail/devicetree-discuss/2011-January/003936.html