Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754337AbbFEXAy (ORCPT ); Fri, 5 Jun 2015 19:00:54 -0400 Received: from skprod3.natinst.com ([130.164.80.24]:35032 "EHLO ni.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752593AbbFEXAt (ORCPT ); Fri, 5 Jun 2015 19:00:49 -0400 From: Jaeden Amero To: Florian Fainelli , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jaeden Amero Subject: [PATCH v4 3/3] net/phy: micrel: Center FLP timing at 16ms Date: Fri, 5 Jun 2015 18:00:26 -0500 Message-Id: <1433545226-18324-4-git-send-email-jaeden.amero@ni.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1433545226-18324-1-git-send-email-jaeden.amero@ni.com> References: <1433545226-18324-1-git-send-email-jaeden.amero@ni.com> X-MIMETrack: Itemize by SMTP Server on US-AUS-MGWOut2/AUS/H/NIC(Release 8.5.3FP6 HF1218|December 12, 2014) at 06/05/2015 06:00:48 PM, Serialize by Router on US-AUS-MGWOut2/AUS/H/NIC(Release 8.5.3FP6 HF1218|December 12, 2014) at 06/05/2015 06:00:48 PM, Serialize complete at 06/05/2015 06:00:48 PM X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2015-06-06_01:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2700 Lines: 79 Link failures have been observed when using the KSZ9031 with HP 1810-8G and HP 1910-8G network switches. Center the FLP timing at 16ms to help avoid intermittent link failures. >From the KSZ9031RNX and KSZ9031MNX data sheets revision 2.2, section "Auto-Negotiation Timing": The KSZ9031[RNX or MNX] Fast Link Pulse (FLP) burst-to-burst transmit timing for Auto-Negotiation defaults to 8ms. IEEE 802.3 Standard specifies this timing to be 16ms +/-8ms. Some PHY link partners need to receive the FLP with 16ms centered timing; otherwise, there can be intermittent link failures and long link-up times. The PHY data sheet recommends configuring the FLP burst registers after power-up/reset and immediately thereafter restarting auto-negotiation, so we center the FLP timing at 16ms and then restart auto-negotiation in the config_init for KSZ9031. Signed-off-by: Jaeden Amero --- drivers/net/phy/micrel.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c index f23765e..499185e 100644 --- a/drivers/net/phy/micrel.c +++ b/drivers/net/phy/micrel.c @@ -366,6 +366,10 @@ static int ksz9021_config_init(struct phy_device *phydev) #define KSZ9031_PS_TO_REG 60 /* Extended registers */ +/* MMD Address 0x0 */ +#define MII_KSZ9031RN_FLP_BURST_TX_LO 3 +#define MII_KSZ9031RN_FLP_BURST_TX_HI 4 + /* MMD Address 0x2 */ #define MII_KSZ9031RN_CONTROL_PAD_SKEW 4 #define MII_KSZ9031RN_RX_DATA_PAD_SKEW 5 @@ -427,6 +431,22 @@ static int ksz9031_of_load_skew_values(struct phy_device *phydev, return ksz9031_extended_write(phydev, OP_DATA, 2, reg, newval); } +static int ksz9031_center_flp_timing(struct phy_device *phydev) +{ + int result; + + /* Center KSZ9031RNX FLP timing at 16ms. */ + result = ksz9031_extended_write(phydev, OP_DATA, 0, + MII_KSZ9031RN_FLP_BURST_TX_HI, 0x0006); + result = ksz9031_extended_write(phydev, OP_DATA, 0, + MII_KSZ9031RN_FLP_BURST_TX_LO, 0x1A80); + + if (result) + return result; + + return genphy_restart_aneg(phydev); +} + static int ksz9031_config_init(struct phy_device *phydev) { const struct device *dev = &phydev->dev; @@ -462,7 +482,8 @@ static int ksz9031_config_init(struct phy_device *phydev) MII_KSZ9031RN_TX_DATA_PAD_SKEW, 4, tx_data_skews, 4); } - return 0; + + return ksz9031_center_flp_timing(phydev); } #define KSZ8873MLL_GLOBAL_CONTROL_4 0x06 -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/