From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Subject: Re: [PATCH 00/14] Rewrite Tegra PCIe driver Date: Thu, 10 Jan 2013 09:34:47 +0100 Message-ID: <20130110093447.646ed07c@skate> References: <1357764194-12677-1-git-send-email-thierry.reding@avionic-design.de> <20130109222517.3c590553@skate> <20130110065537.GC15212@avionic-0098.adnet.avionic-design.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130110065537.GC15212@avionic-0098.adnet.avionic-design.de> Sender: linux-pci-owner@vger.kernel.org To: Thierry Reding Cc: linux-tegra@vger.kernel.org, Grant Likely , Rob Herring , Russell King , Stephen Warren , Bjorn Helgaas , Andrew Murray , Jason Gunthorpe , Arnd Bergmann , devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org List-Id: devicetree@vger.kernel.org Dear Thierry Reding, On Thu, 10 Jan 2013 07:55:37 +0100, Thierry Reding wrote: > The reason is that with the latest bindings the matching of root ports > to device tree nodes works as-is and nothing else indicates that the > emulated host bridge is actually required to make any of this work. So > in order not to introduce unneeded code I've left it out for now. If > somebody decides that we actually need this host bridge (for standards > compliance or whatnot) it could easily be added back. Ok. > However, before the emulated bridge implementation can be merged I think > the PCI ID issue needs to be resolved. Indeed. I am not sure yet how to solve that, though. > > So, I instantiate one unique emulated Host Bridge, and then one > > emulated PCI-to-PCI Bridge for each PCIe interface that I have. > > Oh dear, that's even worse than on Tegra. The Marvell hardware doesn't > even expose the root ports as PCI devices on the bus? My understanding is that no, it doesn't, but I am still figuring out many things in this PCIe topic. > I suppose that in your case it really makes sense because you already > need the emulated PCI-to-PCI bridges and therefore adding an emulated > host bridge doesn't add much. As I said, for Tegra everything still > works without, so I didn't see a reason to add needless code. Ok, thanks! Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com