From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752264AbbASPU0 (ORCPT ); Mon, 19 Jan 2015 10:20:26 -0500 Received: from mout.kundenserver.de ([212.227.126.131]:57152 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751143AbbASPUY convert rfc822-to-8bit (ORCPT ); Mon, 19 Jan 2015 10:20:24 -0500 From: Arnd Bergmann To: Gabriel Fernandez Cc: Jingoo Han , Gabriel FERNANDEZ , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , Russell King , Bjorn Helgaas , Mohit Kumar , Grant Likely , Fabrice Gasnier , Viresh Kumar , Thierry Reding , Minghuan Lian , Magnus Damm , Will Deacon , Tanmay Inamdar , Murali Karicheri , Kishon Vijay Abraham I , Pratyush Anand , Sachin Kamat , Andrew Lunn , Liviu Dudau , Srikanth Thokala , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "kernel@stlinux.com" , linux-pci@vger.kernel.org, Lee Jones Subject: Re: [PATCH 4/5] PCI: designware: Add setup bus-related to pcie_host_ops Date: Mon, 19 Jan 2015 14:54:26 +0100 Message-ID: <6696411.b9yjvPTFJo@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: References: <1418812486-12394-1-git-send-email-gabriel.fernandez@linaro.org> <000e01d01a7f$47592e20$d60b8a60$%han@samsung.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="utf-8" X-Provags-ID: V03:K0:BQPsijKpCDzymso+/XWy8RA6Jh1nO1O8utEmE91Bud7qj0f8WKm 3PrjN69w85GVSQttMvPKWwGK2mJCN/qOq7JMZ9eUUx5keki3ieYuiarLzS2kY1Y6OduhnCx WKkQaE2TY0AkQRoJmnZxNSqbg+MHjQCQCZjvJCAWFI+jrprQnIq1bm1CYQoH7p+RaAzrG2a yBPyITMnvA2a9QF2cx//w== X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 19 January 2015 13:38:53 Gabriel Fernandez wrote: > > On 18 December 2014 at 05:58, Jingoo Han wrote: > > > On Thursday, December 18, 2014 7:16 AM, Arnd Bergmann wrote: > > > On Wednesday 17 December 2014 11:34:45 Gabriel FERNANDEZ wrote: > > > > ST sti SoCs PCIe IPs are built around DesignWare IP Core. > > > > But in these SoCs PCIe IP doesn't support IO. > > I cannot understand how ST sti SoCs PCIe IP does not support I/O. > > As far as I know, it cannot be selected by the 'parameter'. > > Then, H/W engineers dropped out the I/O control logic? > > > > > > > > > > To support this, add setup_bus() to pcie_host_ops. > > > > > > > > > > > > Signed-off-by: Fabrice Gasnier > > > > Signed-off-by: Gabriel Fernandez > > > > > > The dw-pcie driver should be able to tell whether the device has > > > an I/O space or not, and do the right thing based on that. Don't > > > add an implementation specific callback for that. > > > > I agree with Arnd's opinion. > > > > In addition, I have one more question. > > Then, if a device that requires I/O region is connected to > > PCIe slot of ST sti SoCs PCIe, what will happen? > > It just prints error messages? > > > > > Arnd i > n other post mention to add an empty I/O space to workaround lack of I/O > port access. > Is it the right thing to do ? > ​ > http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/299623.html > Good question. Given the latest development, I'd feel tempted to try moving the entire pcie-designware driver to use the generic probing that bypassses pci_common_init_dev(). Rob Herring posted a patch for the versatile PCI driver, you could try doing the same thing here, see http://permalink.gmane.org/gmane.linux.kernel.pci/30346. I think that would completely avoid this problem, and also help everyone that wants to use this driver on arm64. Arnd