Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932499AbbFEWon (ORCPT ); Fri, 5 Jun 2015 18:44:43 -0400 Received: from mail-qc0-f169.google.com ([209.85.216.169]:32789 "EHLO mail-qc0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751742AbbFEWom (ORCPT ); Fri, 5 Jun 2015 18:44:42 -0400 Message-ID: <5572261A.1070801@gmail.com> Date: Fri, 05 Jun 2015 15:43:38 -0700 From: Florian Fainelli User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Jaeden Amero , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/3] net/phy: micrel: Center FLP timing at 16ms References: <1433544046-17595-1-git-send-email-jaeden.amero@ni.com> <1433544046-17595-4-git-send-email-jaeden.amero@ni.com> In-Reply-To: <1433544046-17595-4-git-send-email-jaeden.amero@ni.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3739 Lines: 97 On 05/06/15 15:40, Jaeden Amero wrote: > 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. > > After KSZ9031[RNX or MNX] power-up/reset, program the following > register sequence to set the FLP timing to 16ms > > Write Register Dh = 0x0000 // Set up register address for MMD – Device Address 0h > Write Register Eh = 0x0004 // Select Register 4h of MMD – Device Address 0h > Write Register Dh = 0x4000 // Select register data for MMD – Device Address 0h, Register 4h > Write Register Eh = 0x0006 // Write value 0x0006 to MMD – Device Address 0h, Register 4h > Write Register Dh = 0x0000 // Set up register address for MMD – Device Address 0h > Write Register Eh = 0x0003 // Select Register 3h of MMD – Device Address 0h > Write Register Dh = 0x4000 // Select register data for MMD – Device Address 0h, Register 3h > Write Register Eh = 0x1A80 // Write value 0x1A80 to MMD – Device Address 0h, Register 3h > Write Register 0h, Bit [9] = 1 // Restart Auto-Negotiation Quoting a portion of the data-sheet on how to do this programming is very strange considering that the code is going to be the reference, not the commit message. Other than that, this looks reasonable. > > 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 > -- Florian -- 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/