On Thu, 2017-05-18 at 13:23 +0100, Robin Murphy wrote: > The IOMMU-backed DMA API support has now been in place for a while and > proven stable, so there's no real need to keep most of Juno's SMMUs > disabled. The USB, HDLCDs, and CoreSight ETR all just need to map RAM > buffers for DMA - enabling their SMMUs obviates CPU bounce buffering for > USB's streaming DMA to the upper memory bank, and lets the other two > allocate their relatively large coherent buffers without pressuring CMA. > > Some more software work is still needed for the DMA-330 and PCIe before > those can accommodate SMMU translation correctly in all cases, so we > leave those alone for now. > > Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> > --- For those that don't already know, status = "disabled" for smmu is broken in Linux 4.12-rc1, and this fixes it... https://lkml.org/lkml/2017/5/17/344 > arch/arm64/boot/dts/arm/juno-base.dtsi | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/arch/arm64/boot/dts/arm/juno-base.dtsi b/arch/arm64/boot/dts/arm/juno-base.dtsi > index bfe7d683a42e..02aea43238fc 100644 > --- a/arch/arm64/boot/dts/arm/juno-base.dtsi > +++ b/arch/arm64/boot/dts/arm/juno-base.dtsi > @@ -53,7 +53,6 @@ > #global-interrupts = <1>; > dma-coherent; > power-domains = <&scpi_devpd 0>; > - status = "disabled"; > }; > > gic: interrupt-controller@2c010000 { > @@ -546,7 +545,6 @@ > <GIC_SPI 99 IRQ_TYPE_LEVEL_HIGH>; > #iommu-cells = <1>; > #global-interrupts = <1>; > - status = "disabled"; > }; > > smmu_hdlcd0: iommu@7fb20000 { > @@ -556,7 +554,6 @@ > <GIC_SPI 97 IRQ_TYPE_LEVEL_HIGH>; > #iommu-cells = <1>; > #global-interrupts = <1>; > - status = "disabled"; > }; > > smmu_usb: iommu@7fb30000 { > @@ -567,7 +564,6 @@ > #iommu-cells = <1>; > #global-interrupts = <1>; > dma-coherent; > - status = "disabled"; > }; > > dma@7ff00000 { -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
