Re: [PATCH 1/1] ARC vmac ethernet driver.

[Andreas Fenkart <andreas.fenkart@streamunlimited.com>]

On Tue, Oct 19, 2010 at 06:53:17AM -0700, David Miller wrote:
> From: Andreas Fenkart <andreas.fenkart@streamunlimited.com>
> Date: Fri, 15 Oct 2010 09:54:14 +0200
> 
> > +/* arcvmac private data structures */
> > +struct vmac_buffer_desc {
> > +	unsigned int info;
> > +	dma_addr_t data;
> > +};
> 
> If this is the actual descriptor used by the hardware you
> cannot define it this way.

Changed to this

	/* arcvmac private data structures */
	struct vmac_buffer_desc {
					__le32 info;
					__le32 data;
	};

> 
> dma_addr_t is a variable type, on some platforms it is a
> "u32", on others it is a "u64" but you cannot assume one
> way or another.

Added this check

  if (dma_get_mask(&pdev->dev) > DMA_BIT_MASK(32) ||
      pdev->dev.coherent_dma_mask > DMA_BIT_MASK(32)) {
    dev_err(&pdev->dev, "arcvmac supports only 32-bit DMA addresses\n");
    return -ENODEV;
  }

> 
> Also, are these values big or little endian?  You must use
> the appropriate endian types such as __be32 et al. and then
> access the members using the proper conversion functions.

Using cpu_to_le32 / le32_to_cpu when accessing register map,
buffer descriptors.

Andreas