From patchwork Fri Jun 26 17:38:32 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Fainelli X-Patchwork-Id: 488944 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id AB37F14007F for ; Sat, 27 Jun 2015 03:40:26 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=LnfWun8a; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752229AbbFZRkU (ORCPT ); Fri, 26 Jun 2015 13:40:20 -0400 Received: from mail-pa0-f41.google.com ([209.85.220.41]:33726 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751888AbbFZRkM (ORCPT ); Fri, 26 Jun 2015 13:40:12 -0400 Received: by padev16 with SMTP id ev16so72046566pad.0 for ; Fri, 26 Jun 2015 10:40:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=CYwyb+qrgiQCEmyZtKC9K5Q5BYFvUiTD79KByxl7w1I=; b=LnfWun8avkekaTigC9yodnwYmDOQXr7KhD8UkbfFLtzZuR4+CgiyJXw2QkanjOPTDn RL43L4QH1npKMyB0p+WXBTm6tqoYRqs3Jm3wfi5AGukNCnGnb3SmwgvSyzJ0eaSUCUTZ lBop8/lN3O4VfdUsRZZUpQNsRZrxZgQEfvY0O5dF6VFzyMZD5/SH4i239/S4DPFTTyvW RRA8FybNWYmCIooJw34zN7omWevpzEZlOvoDmsRL4HxqA8AN8vRkkR0AZWb4/yJ81sq0 CVwIhhO7yW6LE3V/DAOkQP3Bx+Dpct2bKS5rVFur+rmLtWIGURYnw6H5+FO+HGHU2Vuj gklg== X-Received: by 10.66.139.234 with SMTP id rb10mr5598739pab.118.1435340411726; Fri, 26 Jun 2015 10:40:11 -0700 (PDT) Received: from fainelli-desktop.broadcom.com (5520-maca-inet1-outside.broadcom.com. [216.31.211.11]) by mx.google.com with ESMTPSA id t9sm33941066pbs.45.2015.06.26.10.40.10 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 26 Jun 2015 10:40:11 -0700 (PDT) From: Florian Fainelli To: netdev@vger.kernel.org Cc: davem@davemloft.net, pgynther@google.com, jaedon.shin@gmail.com, Florian Fainelli Subject: [PATCH net 1/3] net: phy: bcm7xxx: workaround MDIO management controller initial read Date: Fri, 26 Jun 2015 10:38:32 -0700 Message-Id: <1435340314-10229-3-git-send-email-f.fainelli@gmail.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1435340314-10229-1-git-send-email-f.fainelli@gmail.com> References: <1435340314-10229-1-git-send-email-f.fainelli@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The initial MDIO read or write towards the BCM7xxx integrated PHY may fail, workaround this by inserting a dummy MII_BMSR read to force the MDIO management controller to see at least one valid transaction and get out of stuck state out of reset. Signed-off-by: Florian Fainelli --- drivers/net/phy/bcm7xxx.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/phy/bcm7xxx.c b/drivers/net/phy/bcm7xxx.c index 4dea85bfc545..6b701b3ded74 100644 --- a/drivers/net/phy/bcm7xxx.c +++ b/drivers/net/phy/bcm7xxx.c @@ -246,6 +246,13 @@ static int bcm7xxx_28nm_config_init(struct phy_device *phydev) pr_info_once("%s: %s PHY revision: 0x%02x, patch: %d\n", dev_name(&phydev->dev), phydev->drv->name, rev, patch); + /* Dummy read to a register to workaround an issue upon reset where the + * internal inverter may not allow the first MDIO transaction to pass + * the MDIO management controller and make us return 0xffff for such + * reads. + */ + phy_read(phydev, MII_BMSR); + switch (rev) { case 0xb0: ret = bcm7xxx_28nm_b0_afe_config_init(phydev);