lkml.org 
[lkml]   [2007]   [May]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] drivers/ata: Add the SW NCQ support to sata_nv for MCP51/MCP55/MCP61
Alan Cox wrote:
>> That shouldn't be a problem, libata default DMA mask is 32 bits (which
>> isn't overridden with this controller) and so the block layer will
>> bounce any data being read/written above that point with IOMMU or
>> swiotlb. The comment is a bit unnecessarily scary.
>
> Adding a BUG_ON for this would be wise. Its trivial to check and a BUG
> rather than corruption if this assumption ever changes would be far
> preferable

The default DMA mask -everywhere- is 32 bits.

A lot of code will break if this assumption ever changes, not just libata.

Jeff



-
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/

\
 
 \ /
  Last update: 2007-05-18 16:37    [W:0.058 / U:1.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site