Messages in this thread | | | Subject | RE: cciss patches for 2.4.21-rc1, 4 of 4 | From | Arjan van de Ven <> | Date | 25 Apr 2003 16:06:05 +0200 |
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On Fri, 2003-04-25 at 15:48, Miller, Mike (OS Dev) wrote: > I haven't seen any issues (yet) on ia64. I'm running with 5GB RAM. > > mikem > > -----Original Message----- > From: Cameron, Steve > Sent: Friday, April 25, 2003 8:25 AM > Cc: linux-kernel@vger.kernel.org; Miller, Mike (OS Dev) > Subject: RE: cciss patches for 2.4.21-rc1, 4 of 4 > > > > Mike Miller wrote: > > > Changes: > > 1. Sets the DMA mask to 64 bits. Removes RH's code for the DMA mask. > > In order for this to work, it depends on pci_alloc_consistent always > returning memory with physical addresses that fit in 32 bits, > regardless of the DMA mask, since the cciss device's command register > is 32 bits, and the command buffer addresses must fit in there. If > that's the case, this is fine. Otherwise, this may fail if pci_alloc_consistent > returns memory above 4GB. (on x86, I think this is not a problem, not > sure of other archs, e.g. alpha, ia64)
Cameron, lots of people told you numerous times that pci_alloc_consitent is guaranteed to return 32 bit addresses by the API, see Documentation/DMA-mapping.txt for the API definition.
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