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From: Adrian Chadd <adrian@FreeBSD.org>
Date: Mon, 22 Oct 2012 22:32:52 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
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Subject: svn commit: r241918 - head/sys/dev/etherswitch/arswitch
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Author: adrian
Date: Mon Oct 22 22:32:52 2012
New Revision: 241918
URL: http://svn.freebsd.org/changeset/base/241918

Log:
  Don't try to cache the page setting - always set the page before
  doing a switch register read/write.
  
  PR:		kern/172968

Modified:
  head/sys/dev/etherswitch/arswitch/arswitch_reg.c

Modified: head/sys/dev/etherswitch/arswitch/arswitch_reg.c
==============================================================================
--- head/sys/dev/etherswitch/arswitch/arswitch_reg.c	Mon Oct 22 22:29:48 2012	(r241917)
+++ head/sys/dev/etherswitch/arswitch/arswitch_reg.c	Mon Oct 22 22:32:52 2012	(r241918)
@@ -72,10 +72,17 @@ arswitch_split_setpage(device_t dev, uin
 	*phy = (((addr) >> 6) & 0x07) | 0x10;
 	*reg = ((addr) >> 1) & 0x1f;
 
-	if (sc->page != page) {
-		MDIO_WRITEREG(device_get_parent(dev), 0x18, 0, page);
-		sc->page = page;
-	}
+	/*
+	 * The earlier code would only switch the page
+	 * over if the page were different.  Experiments have
+	 * shown that this is unstable.
+	 *
+	 * Hence, the page is always set here.
+	 *
+	 * See PR kern/172968
+	 */
+	MDIO_WRITEREG(device_get_parent(dev), 0x18, 0, page);
+	sc->page = page;
 }
 
 /*