On 04/17/2012 11:10 PM, Hiroshi Doyu wrote: > On Mon, 16 Apr 2012 18:07:06 +0200 > Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: > >> On 04/16/2012 04:10 AM, Hiroshi Doyu wrote: >>> Stephen Warren wrote at Fri, 13 Apr 2012 21:33:47 +0200: >>>> On 04/13/2012 04:22 AM, Hiroshi Doyu wrote: >>>>> Add device tree support for Tegra30 IOMMU(SMMU). >> ... >>>> But why does the SMMU driver expect to control the AHB arbitration >>>> registers? They seem unrelated to the SMMU. >>> >>> It's necessary to inform AHB that SMMU is ready to use. There's a >>> dedicated bit for SMMU in this AHB arbitration register. >> >> Shouldn't there be a dedicated driver for the AHB arbitration registers >> that the SMMU driver calls into to achieve this? IIRC, the AHB >> arbitration registers support much more than the SMMU enable, and if we >> ever need to touch those other features, going to the SMMU driver to do >> so probably wouldn't make sense. > > Agree. Sounds like the way to go. > > We haven't upstreamed AHB driver yet. So is it ok to remove AHB entry > from SMMU dt and add AHB function call when upstreaming AHB driver? > I'll work on that. I think that seems reasonable for now, yes. I assume you mean implementing e.g. arch/arm/mach-tegra/tegra30-ahb.c, similar to how, say, the fuse APIs work. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
