From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from moutng.kundenserver.de ([212.227.126.187]:61186 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755627Ab2FNL6J (ORCPT ); Thu, 14 Jun 2012 07:58:09 -0400 Date: Thu, 14 Jun 2012 13:58:02 +0200 From: Thierry Reding To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, Mitch Bradley , Russell King , Stephen Warren , linux-pci@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, Jesse Barnes , Rob Herring , Colin Cross , linux-tegra@vger.kernel.org Subject: Re: [PATCH v2 07/10] ARM: tegra: pcie: Add device tree support Message-ID: <20120614115802.GA22211@avionic-0098.mockup.avionic-design.de> References: <1339427118-32263-1-git-send-email-thierry.reding@avionic-design.de> <201206141025.09325.arnd@arndb.de> <20120614103127.GA15904@avionic-0098.mockup.avionic-design.de> <201206141106.49142.arnd@arndb.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Dxnq1zWXvFF0Q93v" In-Reply-To: <201206141106.49142.arnd@arndb.de> Sender: linux-pci-owner@vger.kernel.org List-ID: --Dxnq1zWXvFF0Q93v Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jun 14, 2012 at 11:06:48AM +0000, Arnd Bergmann wrote: > On Thursday 14 June 2012, Thierry Reding wrote: > > On Thu, Jun 14, 2012 at 10:25:09AM +0000, Arnd Bergmann wrote: > > > On Thursday 14 June 2012, Thierry Reding wrote: > > > > >=20 > > > > > I believe you will need an "interrupt-map" property here, to map = the host > > > > > interrupts to the INTA-INTD lines of the attached devices. > > > > > > > > Legacy interrupts are something I cannot test at all because I have= no > > > > hardware that supports them. > > >=20 > > > Hmm, I thought all PCIe hardware has to support them when you do not > > > enable MSI. What hardware do you have then? > >=20 > > The TEC (Tamonten Evaluation Carrier) has an FPGA which is connected to= one > > of the Tegra PCIe ports and it only supports MSIs. >=20 > Ah, I see. FPGA based devices often have incomplete PCI support so that > explains why you can't test it. The board also appears to have a > PCIe mini port though, so anything that you could plug in there should > also support LSI interrupts. Yes, I haven't gotten my hands on a suitable module yet, but I'll try. I'm not very familiar with legacy interrupts, though, and I'll have to read up on the interrupt map bindings. > > > > > I'm not sure whether we want to have a device_type=3D"pciex" prop= erty here. > > > > > powerpc and sparc seem to use that information, to distinguish a = pcie > > > > > bus from pci or cardbus. > > > >=20 > > > > That'd be rather useless information given that the Tegra is unlike= ly to > > > > support either PCI or CardBus at some point. > > >=20 > > > But the generic code does not know that. > >=20 > > True. Still there's not much generic code on ARM, so maybe it'd be bett= er to > > add it along with the corresponding code? >=20 > I hope we can make the PCI host probing architecture independent one day, > instead of each architecture implementing their own. I'd say better put > that property in there so we don't have to change it in case the future > generic code will need it. It is part of the binding at > http://www.openfirmware.org/1275/bindings/pci/pci-express.txt after all. There seems to be quite a lot in the PCI core already. Unfortunately every architecture seems to do things differently, so unification is probably goi= ng to be quite difficult. > Note that we should generally not make /code/ be written with the > anticipation of a future extension, but anything that concerns interfaces > to code outside of the kernel (firmware or user space) is best written > in a conservative way to allow later changes. Okay, I'll add the property. Thierry --Dxnq1zWXvFF0Q93v Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iEYEARECAAYFAk/Z0coACgkQZ+BJyKLjJp+6tQCghQ7yYNSKcSJ/x168DKtz4diw smUAoKPRMvXLIpeQy9ohfNgOYvIbWKH3 =cH2h -----END PGP SIGNATURE----- --Dxnq1zWXvFF0Q93v--