From patchwork Tue Nov 23 15:44:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 12634517 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A72DC433F5 for ; Tue, 23 Nov 2021 15:44:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236148AbhKWPrT (ORCPT ); Tue, 23 Nov 2021 10:47:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:34882 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230044AbhKWPrS (ORCPT ); Tue, 23 Nov 2021 10:47:18 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C8C2060E95; Tue, 23 Nov 2021 15:44:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637682250; bh=btRYTaHCmjH9uj+Fvf6SHDefw6YLIZdYbiSMoayTVfk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lVFhe6wdML9M98yJ+t6JZkE/8vfqwN88JusfPM1UTtxMLsTeuC1luqq6jIJ300Piz QYB2x8Wq4THoYPPUh3a4f1pEBly382AoLMn4eP366w4q+g3Mc4e/tN0DH9xKolY5OM PBa9UgedwDQ71K1Jy8zxQdDpYVXUTcNl3WwhIJu+DL4wxf1+Xr46ptVZfhWU+yKiN6 N4C/fDDo83U2QggGOiSbUFCpvGefddwB5CKvzqZD4N5byhlymb53RYOd5RWTOBocaj IT5qT0j2nA9H1HLIkTdxI3wlcQi0Ubesi9U5qkG9eqpuOnkHRddZoMVjHS6KdAOgOV sFIfwo5JcFlfA== From: =?utf-8?q?Marek_Beh=C3=BAn?= To: netdev@vger.kernel.org Cc: Russell King , Jakub Kicinski , Andrew Lunn , davem@davemloft.net, =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH net v2 1/2] net: phylink: Force link down and retrigger resolve on interface change Date: Tue, 23 Nov 2021 16:44:02 +0100 Message-Id: <20211123154403.32051-2-kabel@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211123154403.32051-1-kabel@kernel.org> References: <20211123154403.32051-1-kabel@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: "Russell King (Oracle)" On PHY state change the phylink_resolve() function can read stale information from the MAC and report incorrect link speed and duplex to the kernel message log. Example with a Marvell 88X3310 PHY connected to a SerDes port on Marvell 88E6393X switch: - PHY driver triggers state change due to PHY interface mode being changed from 10gbase-r to 2500base-x due to copper change in speed from 10Gbps to 2.5Gbps, but the PHY itself either hasn't yet changed its interface to the host, or the interrupt about loss of SerDes link hadn't arrived yet (there can be a delay of several milliseconds for this), so we still think that the 10gbase-r mode is up - phylink_resolve() - phylink_mac_pcs_get_state() - this fills in speed=10g link=up - interface mode is updated to 2500base-x but speed is left at 10Gbps - phylink_major_config() - interface is changed to 2500base-x - phylink_link_up() - mv88e6xxx_mac_link_up() - .port_set_speed_duplex() - speed is set to 10Gbps - reports "Link is Up - 10Gbps/Full" to dmesg Afterwards when the interrupt finally arrives for mv88e6xxx, another resolve is forced in which we get the correct speed from phylink_mac_pcs_get_state(), but since the interface is not being changed anymore, we don't call phylink_major_config() but only phylink_mac_config(), which does not set speed/duplex anymore. To fix this, we need to force the link down and trigger another resolve on PHY interface change event. Fixes: 9525ae83959b ("phylink: add phylink infrastructure") Signed-off-by: Russell King (Oracle) Signed-off-by: Marek Behún --- drivers/net/phy/phylink.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c index 3603c024109a..5b8b61daeb98 100644 --- a/drivers/net/phy/phylink.c +++ b/drivers/net/phy/phylink.c @@ -963,6 +963,7 @@ static void phylink_resolve(struct work_struct *w) struct phylink_link_state link_state; struct net_device *ndev = pl->netdev; bool mac_config = false; + bool retrigger = false; bool cur_link_state; mutex_lock(&pl->state_mutex); @@ -976,6 +977,7 @@ static void phylink_resolve(struct work_struct *w) link_state.link = false; } else if (pl->mac_link_dropped) { link_state.link = false; + retrigger = true; } else { switch (pl->cur_link_an_mode) { case MLO_AN_PHY: @@ -1000,6 +1002,15 @@ static void phylink_resolve(struct work_struct *w) /* Only update if the PHY link is up */ if (pl->phydev && pl->phy_state.link) { + /* If the interface has changed, force a + * link down event if the link isn't already + * down, and re-resolve. + */ + if (link_state.interface != + pl->phy_state.interface) { + retrigger = true; + link_state.link = false; + } link_state.interface = pl->phy_state.interface; /* If we have a PHY, we need to update with @@ -1042,7 +1053,7 @@ static void phylink_resolve(struct work_struct *w) else phylink_link_up(pl, link_state); } - if (!link_state.link && pl->mac_link_dropped) { + if (!link_state.link && retrigger) { pl->mac_link_dropped = false; queue_work(system_power_efficient_wq, &pl->resolve); } From patchwork Tue Nov 23 15:44:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 12634519 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75280C433EF for ; Tue, 23 Nov 2021 15:44:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236345AbhKWPrU (ORCPT ); Tue, 23 Nov 2021 10:47:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:34892 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236330AbhKWPrT (ORCPT ); Tue, 23 Nov 2021 10:47:19 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 56A9460F9D; Tue, 23 Nov 2021 15:44:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637682251; bh=OLhgtLiZ098SPvaox7Xvh4plbAgGDAJ9PdtCzmjKwEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m8pD31JblxsYNDLVUpVWoXlFMGsRTaDOf82cCtnuAN3ktoAN82lWGeLE7ftbJ3kOo 2XEGShyIfvzWnlwNKVOY9vJl6C5sf5RVFQ1YJkPtN9Lc3HmHhCldHOneM6+5uxcPIh 2cy7c8/2CSqfmJFOFt8lq1YyBCmp29/ktIrn2GeNY84vNgoglqcpvydNGLwwG+bXnH SBdYzVovv6lnQI/+GjI40OwD67/YW8PZSmTkMCi4lnljUV8f7gWBR+zeiy5gC4IJEI 5+nXFesvWJKsxkfeA/djxxWtdUYTCBhWMxZh1JOwQblzBYHWhPxerp9CIWWF/EFsik 1N+KN3O5NkmEw== From: =?utf-8?q?Marek_Beh=C3=BAn?= To: netdev@vger.kernel.org Cc: Russell King , Jakub Kicinski , Andrew Lunn , davem@davemloft.net, =?utf-8?q?Marek_Beh=C3=BAn?= Subject: [PATCH net v2 2/2] net: phylink: Force retrigger in case of latched link-fail indicator Date: Tue, 23 Nov 2021 16:44:03 +0100 Message-Id: <20211123154403.32051-3-kabel@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211123154403.32051-1-kabel@kernel.org> References: <20211123154403.32051-1-kabel@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: "Russell King (Oracle)" On mv88e6xxx 1G/2.5G PCS, the SerDes register 4.2001.2 has the following description: This register bit indicates when link was lost since the last read. For the current link status, read this register back-to-back. Thus to get current link state, we need to read the register twice. But doing that in the link change interrupt handler would lead to potentially ignoring link down events, which we really want to avoid. Thus this needs to be solved in phylink's resolve, by retriggering another resolve in the event when PCS reports link down and previous link was up, and by re-reading PCS state if the previous link was down. The wrong value is read when phylink requests change from sgmii to 2500base-x mode, and link won't come up. This fixes the bug. Fixes: 9525ae83959b ("phylink: add phylink infrastructure") Signed-off-by: Russell King (Oracle) Signed-off-by: Marek Behún --- drivers/net/phy/phylink.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c index 5b8b61daeb98..eacbb0e6a24b 100644 --- a/drivers/net/phy/phylink.c +++ b/drivers/net/phy/phylink.c @@ -994,6 +994,19 @@ static void phylink_resolve(struct work_struct *w) case MLO_AN_INBAND: phylink_mac_pcs_get_state(pl, &link_state); + /* The PCS may have a latching link-fail indicator. + * If the link was up, bring the link down and + * re-trigger the resolve. Otherwise, re-read the + * PCS state to get the current status of the link. + */ + if (!link_state.link) { + if (cur_link_state) + retrigger = true; + else + phylink_mac_pcs_get_state(pl, + &link_state); + } + /* If we have a phy, the "up" state is the union of * both the PHY and the MAC */