From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net-2.6 PATCH 5/6] e1000e: delay second read of PHY_STATUS register on failure of first read Date: Wed, 01 Jul 2009 16:28:50 -0700 Message-ID: <20090701232850.20555.69711.stgit@localhost.localdomain> References: <20090701232731.20555.63487.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, gospo@redhat.com, Bruce Allan , Jeff Kirsher To: davem@davemloft.net Return-path: Received: from qmta05.emeryville.ca.mail.comcast.net ([76.96.30.48]:54430 "EHLO QMTA05.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752640AbZGAX3D (ORCPT ); Wed, 1 Jul 2009 19:29:03 -0400 In-Reply-To: <20090701232731.20555.63487.stgit@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: From: Bruce Allan Some PHYs may require two reads of the PHY_STATUS register to determine the link status. If the PHY is being accessed by another thread it is possible the first read could timeout and fail. In this case, put a delay in so the second read will pick up the correct link status. Signed-off-by: Bruce Allan Signed-off-by: Jeff Kirsher --- drivers/net/e1000e/phy.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/drivers/net/e1000e/phy.c b/drivers/net/e1000e/phy.c index d845394..994401f 100644 --- a/drivers/net/e1000e/phy.c +++ b/drivers/net/e1000e/phy.c @@ -1531,7 +1531,12 @@ s32 e1000e_phy_has_link_generic(struct e1000_hw *hw, u32 iterations, */ ret_val = e1e_rphy(hw, PHY_STATUS, &phy_status); if (ret_val) - break; + /* + * If the first read fails, another entity may have + * ownership of the resources, wait and try again to + * see if they have relinquished the resources yet. + */ + udelay(usec_interval); ret_val = e1e_rphy(hw, PHY_STATUS, &phy_status); if (ret_val) break;