From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: Some IDE issues with 2.6.28 on PC-Engines ALIX2 Date: Mon, 05 Jan 2009 20:47:22 +0300 Message-ID: <496247AA.1040809@ru.mvista.com> References: <49615667.9020408@iwl.com> <496200A3.2000906@ru.mvista.com> <20090105133340.050858bb@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from h155.mvista.com ([63.81.120.155]:61650 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752137AbZAERqr (ORCPT ); Mon, 5 Jan 2009 12:46:47 -0500 In-Reply-To: <20090105133340.050858bb@lxorguk.ukuu.org.uk> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: "Martin K. Petersen" , Karl Auerbach , linux-ide@vger.kernel.org, karl@cavebear.com Hello. Alan Cox wrote: >>>The IDE interface of the Geode CS5536 companion chip is a completely >>>different beast. It's a more or less standard AMD 8111 PCI IDE device >>>with slightly different timings. >> I'm not sure I uderstand the passage about "slightly different >>timings"... > The timing values used are different to those on the AMD 8111 even though > the interface is similar. What do you mean by timing values anyway, clock counts or the register encoding itself? >> It's stange that the driver is using CPI config. space by default >>which not even documented in the datasheet. I guess the MSR accesses are > The PCI configuration is the portable way to drive it. Portable to what? As you have yorself noted below, this is Geode -- and I highly doubt that CS5536 will be used for anything else. >>also somewhat faster because one doesn't have to access the address/data >>register pair at ports 0xcf8/0xcfc... > This is a Geode. I know. :-) I have hacked on older Geode GX2 for some time back in 2004 (although not on something related to PCI); my "toy" board has RIP just recently.) > What makes you think there is even a PCI bus I sure know that it's not PCI (IIUC, it's the common tendency in the x86 north-to-south-bridge busses has been emulating the PCI config. space with less and less PCI compatible "physical layer"). That does mean emulating PCI config. space mechanism #1 and Geode's not an exception here, see: http://www.amd.com/files/connectivitysolutions/geode/geode_gx/32663C_lx_gx_pciconfig.pdf > or that the 8111 interface isn't entirely a software construct. If that's the case (looks like so), it makes using it even appealing... > Geode PCI hardware is mostly smoke and mirrors ;) When it comes to their internal controllers, yes (though e.g. their OHCI seem to have the real PCI config. space). > Alan WBR, Sergei