From mboxrd@z Thu Jan 1 00:00:00 1970 From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni) Date: Tue, 30 Dec 2014 18:20:50 +0100 Subject: [PATCH 0/6] ARM: mvebu: mvebu-mbus and I/O coherency fixes In-Reply-To: <20141230162716.GC24811@lunn.ch> References: <1419943428-18491-1-git-send-email-thomas.petazzoni@free-electrons.com> <20141230162716.GC24811@lunn.ch> Message-ID: <20141230182050.0550ccdc@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Dear Andrew Lunn, On Tue, 30 Dec 2014 17:27:16 +0100, Andrew Lunn wrote: > [PATCH 1/6] dt: bindings: update mvebu-mbus DT binding with new > branch dt for next merge window, since it is not strictly a fix. Right. > [PATCH 2/6] bus: mvebu-mbus: fix support of MBus window 13 > branch fixes for next -rc Correct. > [PATCH 3/6] ARM: mvebu: fix compatible strings of MBus on Armada 375 and Armada 38x > branch fixes for next -rc Correct, since this is needed for PATCH 2/6 to work properly. > [PATCH 4/6] bus: mvebu-mbus: make sure SDRAM CS for DMA don't overlap the MBus bridge window > branch drivers for next merge window. I assume it is only a run time dependency for the > mv_cesa patches? Indeed, next merge window is good enough for this one: the mv_cesa patches have not even been posted yet. I'm not sure whether the mv_cesa stuff will be ready for 3.20, or 3.21 anyway. But having for sure this mvebu-mbus improvement already scheduled for 3.20 means one less dependency to handle when we'll submit the mv_cesa patches. > [PATCH 5/6] bus: mvebu-mbus: use automatic I/O synchronization barriers > branch fixes for next -rc Right. > [PATCH 6/6] ARM: mvebu: use arm_coherent_dma_ops > Here i'm unsure. Is this a fix, or a cleanup? It's a fix, because it is what brings this part of the cover letter: * It allows to switch to use the existing arm_coherent_dma_ops instead of mvebu specific DMA operations. arm_coherent_dma_ops make sure that DMA coherent mappings are mapped cacheable (which is possible in a cache-coherent platform), which is a necessary to make sure that both CPU-side and device-side accesses are done in a cacheable way. Without this, CPU-side accesses to DMA coherent mappings were made uncached, while device-side accesses were made in a cacheable way, leading to potentially unpredictable behavior. Which is really a fix. So it should go in 3.19-rc. Thanks! Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com