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 110593939D1 for ; Wed, 25 Feb 2026 10:59:15 +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=1772017158; cv=none; b=PoDUgfG1bjcyHpXWQ1KduSIdfExJVxvL3F92uMMBn96i1x6hQUUKXGZcoom/bAobGCXaxezlH5SyRgjgxl8saF4c9v5AjytO7oV7wtxcA2zXjCaspzo1Mi1qVcesNhr7uVmZjbOPxgkzaePhiB9gduP4oywzkGM+t28rXFXfEVI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772017158; c=relaxed/simple; bh=Db3xaViep4xadUj5hbJ5gSJqVKu5FIQCIs8XzQEZQ0A=; h=MIME-Version:Date:From:To:Cc:Subject:In-Reply-To:References: Message-ID:Content-Type; b=W5M7REgO9UPZT324s/nvUTCsoLKR9suBGVeMD0DlULMrDoR3HTUYMkg1iVgSs14Ffh+Mb05nYJmI8TKBcCebMgi4TykYMfgrIJ300/BGGlgiZWJxX4esJXXF1fQ2eseL5IhpraLmuoMR1OQyCClLAiDZy2WB6uJ87CVGB81agcA= 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=hguYhiFZ; 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="hguYhiFZ" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 7F34DA0364; Wed, 25 Feb 2026 11:56:28 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tipi-net.de; s=dkim; t=1772016990; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=cs+8QaoJrfxu3M8QiX2ghjZkw5IxXgF958u8DoGV4+w=; b=hguYhiFZ9RIn1u09sA0kFaubEHdLjzUTC1t4ac1QsxpTw9AFX4+Ckby7n3nlGY7JbQ236z dnJ0EHo37l3/14shv9zbqNkXX50E4hcSmy0RdxA/z+J8Lgyc24hGtB6kGjb6lbvR3tBSNc +SXRYQI116yYv+fx5Odzdy90Ihi8/SGW32+WZgK8GKTfE3bcGgq6K+QgPDf4fLguaj3Yhg JhC33OJr1Let2GyHPPSq9V6vulYuYINAXYMsrTVfI0sTFCDv/uGR6KQvYGkXwoFzT2ET/4 egqaTRQe+2x+/qtuTh0v1PCgCwx2Frkn1UYsXzKpixdooHrIU+1EmA03QX7SzA== Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Wed, 25 Feb 2026 11:56:28 +0100 From: Nicolai Buchwitz To: netdev@vger.kernel.org Cc: andrew+netdev@lunn.ch, claudiu.beznea@tuxon.dev, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, nicolas.ferre@microchip.com, pabeni@redhat.com, linux@armlinux.org.uk, phil@raspberrypi.com Subject: Re: [PATCH net-next v3 0/5] net: cadence: macb: add IEEE 802.3az EEE support In-Reply-To: <20260225091558.51157-1-nb@tipi-net.de> References: <20260225091558.51157-1-nb@tipi-net.de> Message-ID: <6c78119ff230910805372d155ef57fe9@tipi-net.de> X-Sender: nb@tipi-net.de Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-Last-TLS-Session-Version: TLSv1.3 On 25.2.2026 10:15, Nicolai Buchwitz wrote: > Add Energy Efficient Ethernet (IEEE 802.3az) support to the Cadence GEM > (macb) driver using phylink's managed EEE framework. The GEM MAC has > hardware LPI registers but no built-in idle timer, so the driver > implements software-managed TX LPI using a delayed_work timer while > delegating EEE negotiation and ethtool state to phylink. > > Changes from v2: > - macb_tx_lpi_set() now returns bool indicating whether the register > value actually changed, avoiding redundant writes. > - Removed tx_lpi_enabled field from struct macb; LPI state is tracked > entirely within the spinlock-protected register read/modify/write. > - macb_tx_lpi_wake() uses the return value of macb_tx_lpi_set() to > skip the cancel/udelay when TXLPIEN was already clear. > All changes based on feedback from Russell King. > Apologies for the missing subject prefix and version tags on this series - should have been [PATCH net-next v3]. I'm still fairly new to the kernel mailing list workflow and building up the muscle memory around git-format-patch/send-email. I'll resend as v4 with the proper tags. In the meantime, feedback on the code itself is very welcome. > Changes from v1: > - Rewrote to use phylink managed EEE (mac_enable_tx_lpi / > mac_disable_tx_lpi callbacks) instead of the obsolete > phy_init_eee() approach, as recommended by Russell King. > - ethtool get_eee/set_eee are now pure phylink passthroughs. > - Removed all manual EEE state tracking from mac_link_up/down; > phylink handles the lifecycle. > > The series is structured as follows: > > 1. Register definitions: LPI counter offsets (0x270-0x27c), TXLPIEN > bitfield (NCR bit 19), and MACB_CAPS_EEE capability flag. > > 2. LPI statistics: Expose the four hardware EEE counters (RX/TX LPI > transitions and time) through ethtool -S, accumulated in software > since they are clear-on-read. > > 3. TX LPI engine: phylink mac_enable_tx_lpi / mac_disable_tx_lpi > callbacks with a delayed_work-based idle timer. LPI entry is > deferred 1 second after link-up per IEEE 802.3az. Wake before > transmit with a conservative 50us PHY wake delay. > > 4. ethtool EEE ops: get_eee/set_eee delegating to phylink for PHY > negotiation and timer management. > > 5. RP1 enablement: Set MACB_CAPS_EEE for the Raspberry Pi 5's RP1 > southbridge (Cadence GEM_GXL rev 0x00070109 + BCM54213PE PHY). > > Tested on Raspberry Pi 5 (1000BASE-T, BCM54213PE PHY, 250ms LPI timer): > > iperf3 throughput (no regression): > TCP TX: 937.8 Mbit/s (EEE on) vs 937.0 Mbit/s (EEE off) > TCP RX: 936.5 Mbit/s both > > Latency (ping RTT, small expected increase from LPI wake): > 1s interval: 0.273 ms (EEE on) vs 0.181 ms (EEE off) > 10ms interval: 0.206 ms (EEE on) vs 0.168 ms (EEE off) > flood ping: 0.200 ms (EEE on) vs 0.156 ms (EEE off) > > LPI counters (ethtool -S, 1s-interval ping, EEE on): > tx_lpi_transitions: 112 > tx_lpi_time: 15574651 > > Zero packet loss across all tests. Also verified with > ethtool --show-eee / --set-eee and cable unplug/replug cycling. > > Nicolai Buchwitz (5): > net: cadence: macb: add EEE register definitions and capability flag > net: cadence: macb: add EEE LPI statistics counters > net: cadence: macb: implement EEE TX LPI support > net: cadence: macb: add ethtool EEE support > net: cadence: macb: enable EEE for Raspberry Pi RP1 > > drivers/net/ethernet/cadence/macb.h | 20 ++++ > drivers/net/ethernet/cadence/macb_main.c | 136 ++++++++++++++++++++++- > 2 files changed, 155 insertions(+), 1 deletion(-) Nicolai