Subject: Re: dma_alloc_init badness ??

From: David Woodhouse <[email-masked]>
Date: Tue, 20 Jul 2004 18:00:57 -0400

On Tue, 2004-07-20 at 13:26 +0200, Demke, Torsten wrote:
> Hello all,
>
> Im currently porting our application from 2.4.22 to 2.6.
> CPU is MPC852T and the bootloader is u-boot.
>
> The kernel boot prints a warning in dma_alloc_init,
> but Im not sure what that exactly means, and how to solve
> the problem:(
> Can anybody here please give me some help?

	...

> Badness in dma_alloc_init at arch/ppc/kernel/dma-mapping.c:342

The warning at line 342 of dma-mapping.c is:

		WARN_ON(!pmd_none(*pmd));

It's bitching that there's already a page table entry at the virtual
address you've given as CONFIG_CONSISTENT_START. The range specified by
CONFIG_CONSISTENT_START and CONFIG_CONSISTENT_SIZE must be a range of
_virtual_ addresses which are unused in your kernel.

--
dwmw2

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