Re: is_device_dma_capable

From: Malcom Blaney
Date: Tue Jun 16 2009 - 04:23:33 EST

Hi Fujita,

2009/6/16 FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>:
> You use X86_32, right?

I have CONFIG_X86_32=y in my config file.

> In 2.6.25, X86_32 and X86_64 had the own dma_alloc_coherent
> implementations; X86_32 accepted a device having dma_mask that is not
> initialized however X86_64 didn't, I think.
> When we merged them, we chose to prohibit a device having dma_mask
> that is not initialized. I'm not sure the DMA docs say this but IMO
> it's good to require drivers to set up dma_mask (and
> coherent_dma_mask) properly if the drivers want DMA.

If you could point me in the direction of how to set these values
correctly, I would appreciate it.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at