From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f180.google.com (mail-pd0-f180.google.com [209.85.192.180]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 31CD12C02A8 for ; Fri, 31 May 2013 16:44:00 +1000 (EST) Received: by mail-pd0-f180.google.com with SMTP id 14so1673337pdc.25 for ; Thu, 30 May 2013 23:43:58 -0700 (PDT) Date: Fri, 31 May 2013 14:43:49 +0800 From: Kevin Hao To: Scott Wood Subject: Re: [PATCH 1/3] powerpc/mpc85xx: remove the unneeded pci init functions for corenet ds board Message-ID: <20130531064348.GC16514@pek-khao-d1.corp.ad.wrs.com> References: <1369137900-5748-1-git-send-email-haokexin@gmail.com> <1369137900-5748-2-git-send-email-haokexin@gmail.com> <1369781529.18630.25@snotra> <20130530102034.GB18702@pek-khao-d1.corp.ad.wrs.com> <1369940099.14679.14@snotra> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Pk6IbRAofICFmK5e" In-Reply-To: <1369940099.14679.14@snotra> Cc: linuxppc List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --Pk6IbRAofICFmK5e Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 30, 2013 at 01:54:59PM -0500, Scott Wood wrote: > On 05/30/2013 05:20:34 AM, Kevin Hao wrote: > >On Tue, May 28, 2013 at 05:52:09PM -0500, Scott Wood wrote: > >> On 05/21/2013 07:04:58 AM, Kevin Hao wrote: > >> >It also seems that we don't support ISA on all the current > >corenet ds > >> >boards. So picking a primary bus seems useless, remove that > >function > >> >too. > >> > >> IIRC that was due to some bugs in the PPC PCI code in the absence of > >> any primary bus. > > > >Do you know more about these bugs? >=20 > Not off the top of my head -- either search the archives or ask Ben. >=20 > >> fsl_pci_assign_primary() will arbitrarily pick one > >> to be primary if there's no ISA. Have the bugs been fixed? > > > >I know there should be some reason that we put the > >fsl_pci_assign_primary() > >here. But frankly I am not sure what bugs this workaround try to > >fix. For these > >corenet boards picking one to be primary has no effect to the > >64bit kernel. > >And for 32bit kernel, the only effect of this is that isa_io_base > >is set to the > >io virtual base of the primary bus. But the isa_io_base only make > >sense when > >we do have a isa bus, so that we can access some well-known io > >ports directly > >by using outx/inx. But if we don't have isa bus on the board, the > >value of > >isa_io_base should make no sense at all. So we really don't need > >to pick a > >fake primary bus. Of course I may miss something, correct me if I > >am wrong. :-) >=20 > outx/inx can also be used for PCI I/O BARs. Yes, I know there is also PIO. But the value of isa_io_base doesn't have any effect for this. Thanks, Kevin >=20 > -Scott --Pk6IbRAofICFmK5e Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQEcBAEBAgAGBQJRqEakAAoJEJNY7TDerrFxd9oIAIvNMMUEiV1LOmMIzYNjpO7I ThOVr7YobqeLuegE++KwHA1SjgOZJWADbYSg0mx8+RGXf4CJf/7o6UAFV4DCtFpj ExXFc1MhDjEV0AKtwzzQ2Lq8fNShgSDWaZUNCOzUYt75i2dMzUgQZ3bSiYKVs1Fz c/nztLkLi2GpFaxdSOVmBHCCxDGj86A+TDgrGev9GN6eIWIbNgJm906sFCFtCCyd NG5S8sf7WI3WOdxc8PuTMSz9qpDwZ6vvLiw2tMqjdqlaOgPNzM0yIOwQITvJ8NGZ Qu+3MhkJOOYiuR6f1DU28HjRt7I58XojP3jpKsnyeMAQWy54+OHC2rcS3iUFQ1s= =eSmZ -----END PGP SIGNATURE----- --Pk6IbRAofICFmK5e--