From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.dspace.de (mail2.dspace.de [80.228.58.149]) (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 9F1A324E016; Thu, 10 Sep 2026 11:39:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.228.58.149 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789040401; cv=none; b=rXrZ4+KBTN8NnHRBzZuC30LyWAsL2XoGneGM1m57abP9vVtVd99HhWZx0VksGbRyLxLcxHoI8q6s9QS5dus6ExWR/WGFVg0nKzl7KUgXquLJACPc+NlPygJJgBk8qstC91pOuOgHJQqPxerQXVjgqbA0B2dupfOOgLfo5mnapnQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789040401; c=relaxed/simple; bh=MuI5ZoR2KmXDo0xgTJySRZJ9mUPPeEsyxMoAaattzLs=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=cnXOTDiDD06wOnGzJt/G5/XtVnFBOdbboQqbUONjuMi1DNQ9c8jYMf5BGkXtiT9DiFdllIjWnIgEbG3YWSM1NR+2yERzLrIOY5OasiTpwBuMpr1IG8KkCN5FTfwLgqwARiT+hy2PJIhmEvTTQ71sY9pbV2rqQZrRVIsW+slcbUQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=dspace.de; spf=pass smtp.mailfrom=dspace.de; dkim=pass (1024-bit key) header.d=dspace.de header.i=@dspace.de header.b=EbH9j6uX; arc=none smtp.client-ip=80.228.58.149 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=dspace.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=dspace.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=dspace.de header.i=@dspace.de header.b="EbH9j6uX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dspace.de; i=@dspace.de; q=dns/txt; s=dkim1; t=1789040398; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=cCdgCovM884FfdUWP8JorqJdxM/aXjJe2TbERbkQhls=; b=EbH9j6uXWd9L0jhjI1h9vaq+85KC6h/LX1RGPHDggZAtk+0HGOMQn4BJ pFfy7TacE54CdY2xAs+m/gsBmBjY1zGvwj7nG/+qQH0V/4r3C+xHrrDf4 VdfKkk8oDNVdUqQeUaUZrLln8bfnvfIZ8qqewe09HwtAFHMxS+Owo9paM s=; X-CSE-ConnectionGUID: RGGjoQFnRrSdIgTK5XABdQ== X-CSE-MsgGUID: WQgWWFUlTiSxiE+/M71TNA== X-IronPort-AV: E=Sophos;i="6.27,95,1787004000"; d="scan'208";a="5467928" Received: from unknown (HELO Z1-1000) ([10.1.1.222]) by mail.dspace.de with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 10 Sep 2026 13:39:55 +0200 Received: from VM-Z1-1000-LIVE.dspace.de (localhost [127.0.0.1]) by Z1-1000 (Postfix) with ESMTP id 7578960037; Thu, 10 Sep 2026 13:39:55 +0200 (CEST) Received: from exchange.dspace.de (EX-DE-PAD-SE.dspace.de [10.100.196.14]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by Z1-1000 (Postfix) with ESMTPS id 6895260036; Thu, 10 Sep 2026 13:39:55 +0200 (CEST) Received: from PascalKW11-NB.dspace.de (10.71.5.241) by EX-DE-PAD-SE.dspace.de (10.100.196.14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.45; Thu, 10 Sep 2026 13:39:55 +0200 From: Pascal Kneuper To: Tony Nguyen , Przemek Kitszel , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni CC: Daniel Baldin , intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pascal Kneuper Subject: [PATCH net 1/2] igb: Preserve RXPBS.CFG_TS_EN in igb_setup_tx_mode Date: Thu, 10 Sep 2026 13:38:53 +0200 (CEST) Message-ID: <20260910113854.13279-2-PKneuper@dspace.de> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260910113854.13279-1-PKneuper@dspace.de> References: <20260910113854.13279-1-PKneuper@dspace.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-ClientProxiedBy: EX-DE-PAD-SE.dspace.de (10.100.196.14) To EX-DE-PAD-SE.dspace.de (10.100.196.14) X-C2ProcessedOrg: 563f5800-21cf-4d8d-8aed-fddd1469e4ee Content-Transfer-Encoding: quoted-printable X-TBoneOriginalFrom: Pascal Kneuper X-TBoneOriginalTo: Tony Nguyen , Przemek Kitszel , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni X-TBoneOriginalCC: Daniel Baldin , intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pascal Kneuper X-TBoneDomainSigned: false Commit 05f9d3e1ae6e ("igb: Add support for CBS offload") restores the i21= 0 Rx packet buffer size with an unmasked write to RXPBS. Bit 31 of RXPBS is CFG_TS_EN, which enables per-packet Rx timestamping. Writing the register unconditionally clears this bit on every igb_up() (link down/up, MTU change, or driver reset). Like other drivers (igc, i40e, ice), igb intends timestamping settings to persist across link changes: igb_reset() calls igb_ptp_reset() to re-appl= y tstamp_config and set CFG_TS_EN with queues stopped. igb_up() then clears it immediately afterwards, undoing its own restore. igb_ptp_hwtstamp_get() returns cached settings and never reads the register, masking the fallback to software timestamps. On an i210, a link flap increases PTP path delay from <1us to tens of microseconds. Fix by masking the buffer size field, as the FQTSS branch already does. Fixes: 05f9d3e1ae6e ("igb: Add support for CBS offload") Signed-off-by: Pascal Kneuper --- drivers/net/ethernet/intel/igb/igb_main.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethe= rnet/intel/igb/igb_main.c index d4a897a8c82c6..0f3c728a07fb1 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -1947,7 +1947,12 @@ static void igb_setup_tx_mode(struct igb_adapter *= adapter) igb_config_tx_modes(adapter, i); } } else { - wr32(E1000_RXPBS, I210_RXPBSIZE_DEFAULT); + /* Preserve RXPBS.CFG_TS_EN so Rx timestamping settings + * persist across link changes. + */ + val =3D rd32(E1000_RXPBS) & E1000_RXPBS_CFG_TS_EN; + wr32(E1000_RXPBS, val | I210_RXPBSIZE_DEFAULT); + wr32(E1000_TXPBS, I210_TXPBSIZE_DEFAULT); wr32(E1000_I210_DTXMXPKTSZ, I210_DTXMXPKTSZ_DEFAULT); =20 --=20 2.47.3