From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Subject: Re: [PATCH 2/2] powerpc: add support for MPIC message register API Date: Tue, 3 May 2011 10:19:21 -0500 Message-ID: <20110503101921.45f31d34@schlenkerla.am.freescale.net> References: <1303232375-25014-1-git-send-email-meador_inge@mentor.com> <1303232375-25014-3-git-send-email-meador_inge@mentor.com> <071A08F2C6A57E4E94D980ECA553F8741959CA@039-SN1MPN1-004.039d.mgd.msft.net> <4DBAED5D.4060906@mentor.com> <071A08F2C6A57E4E94D980ECA553F8741967EC@039-SN1MPN1-004.039d.mgd.msft.net> <20110429123051.4ed1ca01@schlenkerla.am.freescale.net> <071A08F2C6A57E4E94D980ECA553F8741984EE@039-SN1MPN1-004.039d.mgd.msft.net> <4DBED5E9.2070201@mentor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4DBED5E9.2070201-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Hollis Blanchard Cc: Meador Inge , Wood Scott-B07421 , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "openmcapi-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org" , "linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" List-Id: devicetree@vger.kernel.org On Mon, 2 May 2011 09:03:53 -0700 Hollis Blanchard wrote: > On 05/01/2011 08:41 PM, Kushwaha Prabhakar-B32579 wrote: > >> Perhaps an allocator could be added in the same patchset that adds such a > >> user. > > Yaa. It can be done. Otherwise module has to query each message unit for its availability. > > No, instead the system designer should pick one. If it doesn't matter > which one, then the designer is free to pick any. We should avoid resorting to the notion of a "system designer" if possible -- it's hard to avoid it when dealing with partitioning, but it shouldn't be needed for unpartitioned basic driver operation. > An allocator can't work if you're going to mix drivers. For example, > driver A needs MSRG0, and driver B doesn't care. Driver B loads first, > the allocator selects MSGR0; driver A loads and fails. Having an > allocator at all will create this conflict. In the absence of partitioning, no driver should need a specific one. With partitioning, let the system designer mark those resources as reserved so they don't get allocated. :-) -Scott From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 3 May 2011 10:19:21 -0500 From: Scott Wood To: Hollis Blanchard Subject: Re: [PATCH 2/2] powerpc: add support for MPIC message register API Message-ID: <20110503101921.45f31d34@schlenkerla.am.freescale.net> In-Reply-To: <4DBED5E9.2070201@mentor.com> References: <1303232375-25014-1-git-send-email-meador_inge@mentor.com> <1303232375-25014-3-git-send-email-meador_inge@mentor.com> <071A08F2C6A57E4E94D980ECA553F8741959CA@039-SN1MPN1-004.039d.mgd.msft.net> <4DBAED5D.4060906@mentor.com> <071A08F2C6A57E4E94D980ECA553F8741967EC@039-SN1MPN1-004.039d.mgd.msft.net> <20110429123051.4ed1ca01@schlenkerla.am.freescale.net> <071A08F2C6A57E4E94D980ECA553F8741984EE@039-SN1MPN1-004.039d.mgd.msft.net> <4DBED5E9.2070201@mentor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Cc: Meador Inge , Wood Scott-B07421 , "devicetree-discuss@lists.ozlabs.org" , Kushwaha Prabhakar-B32579 , "openmcapi-dev@googlegroups.com" , "linuxppc-dev@lists.ozlabs.org" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2 May 2011 09:03:53 -0700 Hollis Blanchard wrote: > On 05/01/2011 08:41 PM, Kushwaha Prabhakar-B32579 wrote: > >> Perhaps an allocator could be added in the same patchset that adds such a > >> user. > > Yaa. It can be done. Otherwise module has to query each message unit for its availability. > > No, instead the system designer should pick one. If it doesn't matter > which one, then the designer is free to pick any. We should avoid resorting to the notion of a "system designer" if possible -- it's hard to avoid it when dealing with partitioning, but it shouldn't be needed for unpartitioned basic driver operation. > An allocator can't work if you're going to mix drivers. For example, > driver A needs MSRG0, and driver B doesn't care. Driver B loads first, > the allocator selects MSGR0; driver A loads and fails. Having an > allocator at all will create this conflict. In the absence of partitioning, no driver should need a specific one. With partitioning, let the system designer mark those resources as reserved so they don't get allocated. :-) -Scott