Re: [2.6.22.y][PATCH] atl1: disable broken 64-bit DMA

From: Chris Snook
Date: Mon Nov 26 2007 - 11:58:19 EST


Jay Cliburn wrote:
atl1: disable broken 64-bit DMA

[ Upstream commit: 5f08e46b621a769e52a9545a23ab1d5fb2aec1d4 ]

The L1 network chip can DMA to 64-bit addresses, but multiple descriptor
rings share a single register for the high 32 bits of their address, so
only a single, aligned, 4 GB physical address range can be used at a time.
As a result, we need to confine the driver to a 32-bit DMA mask, otherwise
we see occasional data corruption errors in systems containing 4 or more
gigabytes of RAM.

Signed-off-by: Jay Cliburn <jacliburn@xxxxxxxxxxxxx>
Cc: Luca Tettamanti <kronos.it@xxxxxxxxx>
Cc: Chris Snook <csnook@xxxxxxxxxx>

Acked-By: Chris Snook <csnook@xxxxxxxxxx>
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