From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934178AbbJHPSa (ORCPT ); Thu, 8 Oct 2015 11:18:30 -0400 Received: from mout.kundenserver.de ([212.227.126.131]:54647 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933786AbbJHPS2 (ORCPT ); Thu, 8 Oct 2015 11:18:28 -0400 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: Bjorn Helgaas , Mark Rutland , devicetree@vger.kernel.org, Pawel Moll , Ian Campbell , Marc Zyngier , linux-pci@vger.kernel.org, David Daney , Will Deacon , linux-kernel@vger.kernel.org, Rob Herring , David Daney , Kumar Gala , Bjorn Helgaas Subject: Re: [PATCH v4 4/5] PCI: generic: Correct, and avoid overflow, in bus_max calculation. Date: Thu, 08 Oct 2015 17:18:15 +0200 Message-ID: <5178627.ufUfdomGdT@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <5230007.h2fkbnOlh5@wuerfel> References: <1443811443-18878-1-git-send-email-ddaney.cavm@gmail.com> <20151008150243.GC3885@localhost> <5230007.h2fkbnOlh5@wuerfel> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:fMrX1w91KNn+h9CjswOzvRtLq7vim/UoMr3FjnatmT6dvnvdUpb 0KdZ8q9TPKqH7XhRR3519444Zv3awCprx0iDjhFA3As8OPpXQFMjh3v2O77l9NBvBAP0A62 bjpU1mXQOK6AccI8lsA8MGMtbdwfjQiJ3qxmscFKOopydFYi6DasgbhZzO7MGCSBdWPw46f sM99IqRlpMB5/KvSECGtA== X-UI-Out-Filterresults: notjunk:1;V01:K0:6E1x0FrDJ0I=:ilBo7/y5iclf+AzughCnfj KY4oRZAV45EeRcTdaPkcf1B9s7zQleH8Qh6SUdxOibVSfF8Q0+kRoMFYfNb1vlcYFqnkLt1n/ SDkWIkeC1t5n5c4Z7VPbSbK11hAc/lzEUTKiPGqwtU3UcTVdGNzspeHVFfroQA1++oeXJSauK CsQVFQt8TQIgqzQthxnsBajJKs41FJg0Go32/JO8GgqQF26fAMtg1/m6f7wZQin3oHsZx8pmz OWAqsIrgw474C8yvcZnVXx2SsG4xZhuV6wpYtT9nU24+dv9O/WbbjQeHe/VOcg6H+y9RqwNv2 GerMcUWC81jZ0jT071+Q4d0BqN2NNCYCINrnh9Yh6/DcNhaIzricTEbftHM8+m40aHmVa1AF5 SYqK00MQ7uEQUT99YgVgmDMBwzgpWAhFqH7xW07NQwVdBrfrHHsL37cQ8o41eWEHdLFHHRr0K QNrtbajWfbsKO/isOeDyz9LIA/DtAZapMsUuO53tcgbhTMKYUh8qJd81LV8ot4mwVTtlHf8/9 KPKPppJMbd6tdWSCPI8wzQyg6xizil2oUWsRT6rqJzc+hKMhSvMEvNTi3C4TIZzag0e2efaC7 7e6+0TkIcMVmTmu8aSejQbQhFn8ngS3gL/cqRpZa/seOAvKQghq7MNSq6dTr8waGwomU+YXzU ZMAfmvYM2SULLSHyiLRU/2mzYvFr3eMf+VxSrL22fPeMB6XNAsyV7xDR5FRC2gCS6qbGVE8hP UQKQoGYTTp/ZmHTZ Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 08 October 2015 17:11:32 Arnd Bergmann wrote: > > > --- a/Documentation/devicetree/bindings/pci/host-generic-pci.txt > > > +++ b/Documentation/devicetree/bindings/pci/host-generic-pci.txt > > > @@ -34,7 +34,11 @@ Properties of the host controller node: > > > - #size-cells : Must be 2. > > > > > > - reg : The Configuration Space base address and size, as accessed > > > - from the parent bus. > > > + from the parent bus. The base address corresponds to > > > + bus zero, even though the "bus-range" property may specify > > > + a different starting bus number. The driver must only map > > > + or access the portion of the Configuration Space that > > > + corresponds to the "bus-range" > > I thought we had reached an agreement that it is a bad idea to have a 'reg' > property that lists registers belonging to a different device. > > To further clarify: the argument was to make it mirror what ACPI does for PCI. However, this is unlike what all other devices do with DT, where you have non-overlapping register ranges (start, length) for each device. ACPI as far as I understand it does not give a range for a PCIe host, but instead provides a way to get the start address of the ECAM register area for the domain that the host is part of, and that needs to be the same address for each host in the domain. Arnd