From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Thu, 22 May 2014 20:26:19 +0200 Subject: [PATCH v2] ARM: realview: basic device tree implementation In-Reply-To: References: <1399586896-16906-1-git-send-email-linus.walleij@linaro.org> <5057707.jNCXlqf9dH@wuerfel> Message-ID: <5233065.1vXjHiDqN2@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thursday 22 May 2014 14:09:52 Nicolas Pitre wrote: > On Thu, 22 May 2014, Arnd Bergmann wrote: > > > On Thursday 22 May 2014 15:45:03 Catalin Marinas wrote: > > > By making the DMA memory Strongly Ordered, we avoid the > > > L220 write buffer. In addition to the above commit, we also had > > > 2503a5ecd86c (ARM: 6201/1: RealView: Do not use outer_sync() on > > > ARM11MPCore boards with L220). > > > > Ah, so this also stands in the way of multiplatform realview > > Isn't the real value of a multiplatform realview in the ability to use > it with Qemu? Did Qemu go to the extreme of emulating all those cache > issues? The qemu developers have in the past always argued strongly that they want to run the same kernel that runs on real hardware. Having a kernel that runs only on the emulated version but not on actual hardware is clearly against that goal, and we should use CONFIG_ARCH_VIRT for that purpose. Arnd