From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.tipi-net.de (mail.tipi-net.de [194.13.80.246]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66E1833FE05 for ; Mon, 30 Mar 2026 22:47:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.13.80.246 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774910830; cv=none; b=qcAvYMzFXKi9XDasyz10PjHoSP+XmCZxxIVOc8tlH++ODYXy2LdKdecxZrPKV7sE3VQ1Cb8WM8q/62U03qjc3gF0NSVAaGlzwzMm5hRvA1Da7xcct8+hj3LV8dRAWJQmDVX6veDyg/JDr6C4V9xjVSvkciSKbIoX/QaZCG7q61s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774910830; c=relaxed/simple; bh=SJS4sxqjaCFpDx3bZPnmhkMrdFDqUMPe/C2dRIB/ByE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HS5snq31G4wWygUgtoLrGg3PHYtt63kPEisHA6DxGqQH6pUPO2CwB8h43SWM9Ls5bafyuF5ij9wJdK378h3UxojYlT9FhslsiyJxjQukv5jL/H0/ObguxRxHrqexc6BD/goOyE7Ry0/8m87lrG9uDrFGH+ruXA6WC/+cPkZkxCI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tipi-net.de; spf=pass smtp.mailfrom=tipi-net.de; dkim=pass (2048-bit key) header.d=tipi-net.de header.i=@tipi-net.de header.b=42X3MmJT; arc=none smtp.client-ip=194.13.80.246 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tipi-net.de header.i=@tipi-net.de header.b="42X3MmJT" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id C06B4A587E; Tue, 31 Mar 2026 00:47:02 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tipi-net.de; s=dkim; t=1774910823; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding; bh=6APDex8FZSZksu7DvpvXW7Jltmk8KR+z1wOQGR0gc7U=; b=42X3MmJTanejitOaTSvVa5SmebhxqJN/lxsByLk3MV4QnYK2klt8hJnhzfdLcbjmFJHgKE DBOEVpg0fQE0OvbfbadzBZB4QvWPqeRBRs1Oe1VupLw6zhegT6BpiQUyxCj2PLzDUhNrWR LuxJlUZIVYcHJbJo5gXZ3zTRZWW/PwVAuPx4z7QPkgKFgrQueBZ15gRMU6S6dx2z4TXJj+ dtBcbzbr+pB99Qt6klJJr11km11OLPkLQO5rZkbNC0fwRTS2Ai9tkPmpMQ64jkX4iYEgKt v+Dche4X7tS9/Vx+wcdsSAIe16RPnQME1EWzon9qyIwZIsV85iGzWSV2xJzU/A== From: Nicolai Buchwitz To: netdev@vger.kernel.org Cc: Phil Elwell , Nicolai Buchwitz Subject: [PATCH net-next v2 0/2] net: phy: microchip: add downshift support for LAN88xx Date: Tue, 31 Mar 2026 00:46:25 +0200 Message-ID: <20260330224630.579937-1-nb@tipi-net.de> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 Add standard ETHTOOL_PHY_DOWNSHIFT tunable support for the Microchip LAN88xx PHY, following the same pattern used by Marvell and other PHY drivers. Ethernet cables with faulty or missing pairs (specifically C and D) can successfully auto-negotiate 1000BASE-T but fail to establish a stable link. The LAN88xx PHY supports automatic downshift to 100BASE-TX after a configurable number of failed attempts (2-5). Patch 1 adds the get/set tunable implementation. Patch 2 enables downshift by default with a count of 2. Based on an earlier downstream implementation by Phil Elwell. Tested on Raspberry Pi 3B+ (LAN7515/LAN88xx). Changes since v1: - Replace switch statements with FIELD_GET()/FIELD_PREP() (Andrew Lunn) - Drop unused per-count register defines from microchipphy.h Nicolai Buchwitz (2): net: phy: microchip: add downshift tunable support for LAN88xx net: phy: microchip: enable downshift by default on LAN88xx drivers/net/phy/microchip.c | 71 +++++++++++++++++++++++++++++++++++- include/linux/microchipphy.h | 5 +++ 2 files changed, 75 insertions(+), 1 deletion(-) -- 2.51.0