From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from kirk.dutchspace.nl (kirk.dutchspace.nl [193.200.147.14]) by ozlabs.org (Postfix) with ESMTP id EC590DE88B for ; Sat, 19 Apr 2008 00:57:45 +1000 (EST) Message-ID: <4808AED4.7020507@dutchspace.nl> Date: Fri, 18 Apr 2008 16:23:16 +0200 From: Johan Borkhuis MIME-Version: 1.0 To: Christian Ehrhardt Subject: Re: pci issue - wrong detection of pci ressources References: <48088F02.2060806@linux.vnet.ibm.com> In-Reply-To: <48088F02.2060806@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linuxppc-dev@ozlabs.org, Detlev Zundel , Hollis Blanchard List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello Christian, Christian Ehrhardt wrote: > Hi, > I tried to use a radeon r200 based graphic card on a sequoia ppc > (440epx) board. I wondered about the initialization of radeonfb that > failed with > __ioremap(): phys addr 0x0 is RAM lr c029cf80 > radeonfb (0000:00:0a.0): cannot map MMIO > radeonfb: probe of 0000:00:0a.0 failed with error -5 > > I trigger a check in ioremap, because the address it wants to remap is > 0x0 which can never work. The reason of that is that the pci ressource > of that graphic card is not properly detected. > > With some help I found two kernels - one that work and one that has > this issue. > Unfortunately they are very different: > good => 2.6.24.2 from the linux-2.6-denx - built for arch=ppc > bad => we have 2.6.25-rc9 (used in our kvm ppc project atm) - build > for arch=powerpc > I tried building the 2.6.25-rc9 with arch=ppc, but that one does not > boot so far. Because of that I can't surely tell you if it is only > that difference that breaks the pci detection. > We need arch=powerpc for our kvm code anyway, so I hope there is > another solution than to switch to arch=ppc ;-) I came across a similar problem, which (ultimately) was caused by a lack of memory reserved for PCI. I moved from 2.6.14(ppc) to 2.6.20(powerpc), and suddenly some cards stopped working: the BAR registers were not initialized, so it was not possible to access the cards. Have a look at the boot-time messages, especially the early messages, as the PCI subsystem is started very early in the boot process. You could also try switching on PCI-debugging, and have a look at the debug messages, or add some extra debugging info to the pci-initialization code. Kind regards, Johan