From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Tue, 24 Jul 2012 14:18:54 +0000 Subject: [GIT PULL] io.h clean-up for PCI In-Reply-To: <500EA251.1090000@gmail.com> References: <50049285.1060100@gmail.com> <201207241243.55640.arnd@arndb.de> <500EA251.1090000@gmail.com> Message-ID: <201207241418.54637.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tuesday 24 July 2012, Rob Herring wrote: > How is mem_offset supposed to be set? Generally memory is setup as cpu > base paddr = pci mem addr, so mem_offset should be 0? But integrator is > set to the cpu paddr, and it works. I don't really know. I would assume that setting mem_offset to something other than 0 means your bus address space is not the same as the cpu address space. The window that is usable by PCI should be specified in the memory resource, not using the mem_offset, but I could be interpreting that incorrectly. Arnd