From: Vasanthy Kolluri <vkolluri@cisco.com>
Date: Thu, 18 Mar 2010 16:19:44 +0000 (+0000)
Subject: enic: Bug Fix: Fix hardware descriptor reads
X-Git-Tag: v2.6.35-rc1~473^2~743
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a55a603dae47a1ea4fbfad3a3a428ea7a0900ab6;p=pandora-kernel.git

enic: Bug Fix: Fix hardware descriptor reads

The last bit written to a completion descriptor by hardware is the color
bit. Driver must read all other descriptor fields only after reading the
color bit to avoid reading stale descriptor fields.  There is a rmb() after
reading the color bit to avoid any compiler/cpu reordering of the reads.
The color bit is the generation bit that toggles each pass through the
completion descriptor ring.

Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: Vasanthy Kolluri <vkolluri@cisco.com>
Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

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