lkml.org 
[lkml]   [2007]   [Dec]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] sata_nv: fix ADMA ATAPI issues with memory over 4GB (v3)
Robert Hancock wrote:
> Jeff Garzik wrote:
>> Robert Hancock wrote:
>>> This fixes some problems with ATAPI devices on nForce4 controllers in
>>> ADMA mode
>>> on systems with memory located above 4GB. We need to delay setting
>>> the 64-bit
>>> DMA mask until the PRD table and padding buffer are allocated so that
>>> they don't
>>> get allocated above 4GB and break legacy mode (which is needed for ATAPI
>>> devices).
>>>
>>> Signed-off-by: Robert Hancock <hancockr@shaw.ca>
>>
>> This is a bit nasty :/
>>
>> I would consider setting the consistent DMA mask to 32-bit, and
>> setting the overall mask to 64-bit.
>>
>> Seems like that would solve the problem?
>
> The issue with that is that it would also constrain the ADMA CPB/PRD
> table allocation to 32-bit, which I'd rather avoid having to do. There
> are dual-socket Opteron boxes like HP xw9300 that use this controller,
> and limiting the allocation to 32-bit could force a non-optimal node
> allocation for the table memory.
>
> These type of devices really want a version of dma_alloc_coherent that
> allows overriding the DMA mask for specific allocations to make this
> cleaner. I'm sure this isn't the only device that has different DMA mask
> requirements for different consistent memory allocations..
>
> This patch does has the advantage of being confirmed to fix the
> reporter's problem (https://bugzilla.redhat.com/show_bug.cgi?id=351451)
> which there's something to be said for this late in the .24-rc series..
>
>>
>> Also, does this need to be rebased on top of what I just pushed upstream?
>
> It don't think so.. this change is independent from the "sata_nv: don't
> use legacy DMA in ADMA mode (v3)" patch you just merged.

This bug fix is still outstanding. I haven't heard any more comments on
this one recently..

--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/



\
 
 \ /
  Last update: 2007-12-28 22:41    [W:0.072 / U:0.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site