12.01.2017 08:52, Nikita Yushchenko wrote: >>> diff --git a/drivers/staging/fsl-mc/bus/fsl-mc-bus.c b/drivers/staging/fsl-mc/bus/fsl-mc-bus.c >>> index 5ac373c..480b644 100644 >>> --- a/drivers/staging/fsl-mc/bus/fsl-mc-bus.c >>> +++ b/drivers/staging/fsl-mc/bus/fsl-mc-bus.c >>> @@ -540,7 +540,7 @@ int fsl_mc_device_add(struct dprc_obj_desc *obj_desc, >>> >>> /* Objects are coherent, unless 'no shareability' flag set. */ >>> if (!(obj_desc->flags & DPRC_OBJ_FLAG_NO_MEM_SHAREABILITY)) >>> - arch_setup_dma_ops(&mc_dev->dev, 0, 0, NULL, true); >>> + arch_setup_dma_ops(&mc_dev->dev, 0, 0, false, NULL, true); >>> >>> /* >>> * The device-specific probe callback will get invoked by device_add() >> >> Why are these actually calling arch_setup_dma_ops() here in the first >> place? Are these all devices that are DMA masters without an OF node? > > I don't know, but that's a different topic. This patch just adds > argument and sets it to false everywhere but in the location when range > should be definitely enforced. > >>> @@ -126,6 +127,8 @@ void of_dma_configure(struct device *dev, struct device_node *np) >>> return; >>> } >>> dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset); >>> + >>> + enforce_range = true; >>> } >>> >>> dev->dma_pfn_offset = offset; >> >> Hmm, I think when the dma-ranges are missing, we should either enforce >> a 32-bit mask, or disallow DMA completely. It's probably too late for >> the latter, I wish we had done this earlier in order to force everyone >> on ARM64 to have a valid dma-ranges property for any DMA master. > > This can be done over time. > > However the very idea of this version of patch is - keep working pieces > as-is, thus for now setting enforce_range to false in case of no defined > dma-ranges is intentional. What we can do is - check bus width (as it is defined in DT) and set enforce_range to true if bus is 32-bit > What I should re-check is - does rcar dtsi set dma-ranges, and add it if > it does not. It does not, will have to add. In DT bus is defined as 64-bit. But looks like physically it is 32-bit. Maybe DT needs fixing.
