On Wed, Feb 11, 2015 at 12:53:35PM -0500, Murali Karicheri wrote: > diff --git a/drivers/of/device.c b/drivers/of/device.c > index 314c8a9..167ad2d 100644 > --- a/drivers/of/device.c > +++ b/drivers/of/device.c > @@ -90,10 +90,11 @@ void of_dma_configure(struct device *dev, struct device_node *np) > struct iommu_ops *iommu; > > /* > - * Set default dma-mask to 32 bit. Drivers are expected to setup > - * the correct supported dma_mask. > + * Set default coherent_dma_mask to 32 bit. Drivers are expected to > + * setup the correct supported mask. > */ > - dev->coherent_dma_mask = DMA_BIT_MASK(32); > + if (!dev->coherent_dma_mask) > + dev->coherent_dma_mask = DMA_BIT_MASK(32); > > /* > * Set it to coherent_dma_mask by default if the architecture > @@ -102,6 +103,11 @@ void of_dma_configure(struct device *dev, struct device_node *np) > if (!dev->dma_mask) > dev->dma_mask = &dev->coherent_dma_mask; > > + /* > + * Use default size to cover 32 bit. Drivers need to set this in DT > + * to override the same. > + */ > + size = 1ULL << 32; I'm not sure this is needed since on error path the original code would set the size to coherent_dma_mask. > ret = of_dma_get_range(np, &dma_addr, &paddr, &size); > if (ret < 0) { > dma_addr = offset = 0; Here we already have (not seen in the context): size = dev->coherent_dma_mask + 1; > @@ -128,6 +134,15 @@ void of_dma_configure(struct device *dev, struct device_node *np) > > dev->dma_pfn_offset = offset; > > + /* > + * Limit coherent and dma mask based on size and default mask > + * set by the driver. > + */ > + dev->coherent_dma_mask = min(dev->coherent_dma_mask, > + DMA_BIT_MASK(ilog2(dma_addr + size))); > + *dev->dma_mask = min((*dev->dma_mask), > + DMA_BIT_MASK(ilog2(dma_addr + size))); > + > coherent = of_dma_is_coherent(np); > dev_dbg(dev, "device is%sdma coherent\n", > coherent ? " " : " not "); Otherwise it looks fine to me. Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> -- 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