From: Michael Chan <mchan@broadcom.com>
Date: Tue, 28 Aug 2007 22:39:42 +0000 (-0700)
Subject: [BNX2]: Add write posting comment.
X-Git-Tag: v2.6.23-rc5~37^2~8
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=594a9dfae7113d9601b2c353754c40d0b7e00a03;p=linux-2.6

[BNX2]: Add write posting comment.

Add comment to explain why we cannot read back after chip reset
before delaying.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index 00918602ba..854d80c330 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -3934,6 +3934,10 @@ bnx2_reset_chip(struct bnx2 *bp, u32 reset_code)
 		/* Chip reset. */
 		REG_WR(bp, BNX2_PCICFG_MISC_CONFIG, val);
 
+		/* Reading back any register after chip reset will hang the
+		 * bus on 5706 A0 and A1.  The msleep below provides plenty
+		 * of margin for write posting.
+		 */
 		if ((CHIP_ID(bp) == CHIP_ID_5706_A0) ||
 		    (CHIP_ID(bp) == CHIP_ID_5706_A1))
 			msleep(20);