Badness in dma_alloc_init
Kalle Pokki
kalle.pokki at iki.fi
Tue Jan 10 00:35:20 EST 2006
Aristeu Sergio Rozanski Filho wrote:
>Hi!
>
>
>>I'm having some trouble with the DMA allocation using Linux 2.6.14-rc2 +
>>some platform modifications. Namely, the dma_alloc_coherent() function
>>returns bogus virtual addresses causing machine check exceptions. At
>>boot, the kernel complains there is something wrong, but I cannot figure
>>out how to fix it. CONFIG_CONSISTENT_START is at its default value,
>>0xff100000. Any hints where to look further?
>>
>>Oh, this is a custom 8xx board. Has the support for DMA in 8xx been
>>unstable at the time of pre-2.6.14?
>>
>>
>probably your IMAP_ADDR is at 0xff000000, isn't it? if it is, please adjust
>CONFIG_CONSISTENT_START to an address like 0xe0000000.
>
>
>
True, my IMAP_ADDR is at 0xff000000. But IMAP_SIZE is just 64 KB, so
there should be no overlap, right? Or is the IMAP memory area mapped
with an 8-MB TLB entry or something like that?
No badness in dma-mapping.c anymore with CONFIG_CONSISTENT_START being
0xe0000000, however. Thanks.
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