On Friday, June 24, 2016 6:46:48 PM CEST Timur Tabi wrote: > + /* The EMAC itself is capable of 64-bit DMA. If the SOC limits that > + * range, then we expect platform code to adjust the mask accordingly. > + */ > + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); > + if (ret) { > + dev_err(&pdev->dev, "could not set DMA mask\n"); > + return ret; > + } > The comment does not match the code: if the platform has no IOMMU and the bus limit is smaller than the memory, dma_set_mask_and_coherent() will fail, and the driver should instead ensure that the buffers are allocated from the 32-bit area. Alternatively, adjust the comment to explain that this is a limitation in the driver that can be lifted if necessary. Arnd -- 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