From: Jeff Kirsher <redacted>
Date: Tue, 30 Jun 2009 14:44:56 -0700

From: Jesse Brandeburg <redacted>

This patch addresses three WARN_ON statements from DMA-API debug code

ixgbe is mapping more than it unmaps, reduce the length of the map call and
remove the "used once" local variable.

found by Joerg Roedel [off-list ref] in 2.6.30, so is a candidate
for -stable.

in addition, fix missing ->dma = 0 after unmap to prevent double free with
pci_unmap_single

and lastly, don't unmap (half) pages that aren't mapped.

Signed-off-by: Jesse Brandeburg <redacted>
CC: Joerg Roedel <redacted>
Signed-off-by: Jeff Kirsher <redacted>

Applied.