From: thierry.reding@avionic-design.de (Thierry Reding) Date: Wed, 30 Jan 2013 13:03:44 +0100 Subject: [PATCH v2 19/27] pci: PCIe driver for Marvell Armada 370/XP systems In-Reply-To: <20130130113245.GH23505@n2100.arm.linux.org.uk> References: <1359399397-29729-1-git-send-email-thomas.petazzoni@free-electrons.com> <1359399397-29729-20-git-send-email-thomas.petazzoni@free-electrons.com> <20130130113245.GH23505@n2100.arm.linux.org.uk> Message-ID: <20130130120344.GA29490@avionic-0098.mockup.avionic-design.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jan 30, 2013 at 11:32:46AM +0000, Russell King - ARM Linux wrote: > On Mon, Jan 28, 2013 at 07:56:28PM +0100, Thomas Petazzoni wrote: > > +static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev, > > + const struct resource *res, > > + resource_size_t start, > > + resource_size_t size, > > + resource_size_t align) > > +{ > > + if (!(res->flags & IORESOURCE_IO)) > > + return start; > > + > > + /* > > + * The I/O regions must be 64K aligned, because the > > + * granularity of PCIe I/O address decoding windows is 64 K > > + */ > > + return round_up(start, SZ_64K); > > +} > > You do realise that this will result in all PCI I/O BARs being rounded > up to 64K. > > I've just been digging through the PCI code and have come across a > function - pcibios_window_alignment() - which the PCI code allows to be > overriden which allows you to increase the alignment requirement of > bridge windows. It takes the PCI bus and window type as arguments. > > I'd suggest using that, and checking whether the bus which is passed > corresponds with a bus which gives you problems, so that you don't > impose the 64K requirement on downstream bridges. That approach isn't going to work very well with multi-platform, though, since the function can only be overridden on a per-architecture basis. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: not available URL: