From patchwork Mon Nov 22 23:51:54 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: 12633139 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 0148EC4332F for ; Mon, 22 Nov 2021 23:52:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232053AbhKVXzJ (ORCPT ); Mon, 22 Nov 2021 18:55:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:42570 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232007AbhKVXzI (ORCPT ); Mon, 22 Nov 2021 18:55:08 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0C9436101A; Mon, 22 Nov 2021 23:51:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637625121; bh=egm/7DenZTTEK7bHJfVrPa0M9dSi6t5o9PCmnk+J7i4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=blc41oc0wkUYjnp3CWi1e3lu4RQuwnL/CbEJmvVKt4w0TP/xvD27n1aEIXFpAAG0m KL7QNgPO7263OvU0cCQWOqOoK2c6BefDdAO/dHPxUJPsDxmIs11RTgghskg5RbBXcv DUuuiYoyZzK7cJ7+OmNBym9YhEu2mizNLOeuPzlLOqwZJMStRkndCJ6MaZhofdGmbZ Bv9uk0FTa+0eXg8qUoD0rwt20Qxr0f4kynX537oyip7bASaNT501Sr+dk82T51Jd+v QuOy9pQp8RjRJD/lR+Rt2JWtyRS1OzWl5bUkYBKHLi645Lh6cdyofjWtZFTK34gMuV tVUuxabZL2+UQ== 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 2/2] net: phylink: Force retrigger in case of latched link-fail indicator Date: Tue, 23 Nov 2021 00:51:54 +0100 Message-Id: <20211122235154.6392-3-kabel@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211122235154.6392-1-kabel@kernel.org> References: <20211122235154.6392-1-kabel@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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. 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 | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c index 5b8b61daeb98..c6b5d5af8817 100644 --- a/drivers/net/phy/phylink.c +++ b/drivers/net/phy/phylink.c @@ -994,6 +994,12 @@ 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 PCS link goes down, retrigger a resolve. + */ + if (!link_state.link && cur_link_state) + retrigger = true; + /* If we have a phy, the "up" state is the union of * both the PHY and the MAC */