Re: (reposting) how to get DMA'able memory within 4GB on 64-bit m achi ne

From: Jes Sorensen (jes@sunsite.dk)
Date: Thu Jun 28 2001 - 17:20:03 EST


>>>>> "David" == David S Miller <davem@redhat.com> writes:

David> Jes Sorensen writes:
>> Because on ia64 you will get back a 64 bit pointer if you use
>> pci_set_dma_mask() to set a 64 bit mask before calling the pci
>> functions in question.

David> Please note that this is nonstandard and undocumented behavior.

David> This is not a supported API at all, and the way 64-bit DMA will
David> eventually be done across all platforms is likely to be
David> different.

Well please also note there has been requests for proper 64 bit DMA
support for over 3 years or so by now.

The interface we use works well, so why should it be changed for other
architecures? Instead it would make a lot more sense to support it on
other architectures that can do 64 bit DMA.

Jes
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Jun 30 2001 - 21:00:20 EST