From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.chez-thomas.org (hermes.mlbassoc.com [76.76.67.137]) by ozlabs.org (Postfix) with ESMTP id 06A7BB7080 for ; Fri, 26 Feb 2010 10:43:22 +1100 (EST) Message-ID: <4B870B17.7080701@mlbassoc.com> Date: Thu, 25 Feb 2010 16:43:19 -0700 From: Gary Thomas MIME-Version: 1.0 To: Scott Wood Subject: Re: PCI on 834x References: <4B854A93.7030405@mlbassoc.com> <4B85746F.3020200@freescale.com> <4B857AA8.9000208@mlbassoc.com> <4B857EA1.6030605@freescale.com> <4B858243.8010908@mlbassoc.com> <4B858B6C.4020809@freescale.com> <20100224205159.GA6555@oksana.dev.rtsoft.ru> <4B85A4C2.6090007@mlbassoc.com> <4B85B182.2030508@mlbassoc.com> <4B86886B.5000304@mlbassoc.com> <1267130982.23523.1728.camel@pasglop> <4B86E5A7.9090607@freescale.com> <4B86E794.6020403@mlbassoc.com> <4B86EAA3.8000301@freescale.com> In-Reply-To: <4B86EAA3.8000301@freescale.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linuxppc-dev , avorontsov@ru.mvista.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 02/25/2010 02:24 PM, Scott Wood wrote: > Gary Thomas wrote: >> On 02/25/2010 02:03 PM, Scott Wood wrote: >>> Gary, can you check that the MMIO addresses are going to the PCI bus as-is, and aren't being translated down to zero? I.e. POTARn should equal POBARn, and likewise in the device >>> tree's pci node's ranges. >> >> Hmm, that doesn't match with how I've always had this setup. I have: >> POTAR0 = 0x00000000 >> POTBR0 = 0x000C0000 (0xC0000000 >> 12) >> >> My device tree mappings are: >> ranges = <0x02000000 0x0 0xC0000000 0xC0000000 0x0 0x10000000 >> 0x01000000 0x0 0x00000000 0xB8000000 0x0 0x00100000> > > That ranges property says that host address 0xc0000000 maps to PCI address 0xc0000000, so Linux will program the BAR to 0xc0000000, but the actual accesses will go elsewhere > because POTAR0 is zero. > > Setting POTAR to zero is also a bad idea because it's aliasing your DMA window (it may work in certain situations based on who's initiating the transaction, but it seems like it's > asking for trouble), plus it seems some cards just don't like address zero. > > Try setting POTAR0 to 0x000c0000 and see what happens. Sadly, that doesn't work at all - neither RedBoot nor Linux can talk to any of the PCI devices. -- ------------------------------------------------------------ Gary Thomas | Consulting for the MLB Associates | Embedded world ------------------------------------------------------------