Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C446E2494FE; Wed, 25 Feb 2026 01:39:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983541; cv=none; b=R+jVKFhWzKpKyAB57ZLgZqgvzXPNFVatug+yjISMRRefcaHuN606LywtuYO1oHbbZ0hG3D0QlveZUjBVUcoIDZyUveWt/JqzBoF+54LV7syCxUHBM25WcFzOHvkjzIr3GknhsOnxAMYyV9L74kXyzaeT15unGtjGO3l83KXSdyk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983541; c=relaxed/simple; bh=f7zn+o0yNYBYTvjzEMTzJIyybZ8kv2Q14Cn3yIyA/R4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BbsMMh5XsiE4ns1W0gERUcAq608E612oEYLMGFzTvmadSfKoOcwevY6kOvHdJi9rFz3K9buJR5r3Ofv1NqHAhG7hzHnlxS2Yf39nYUEXRU4qogcGVPvzuuj+i8eSeo/qc4Sr+WhVon4XxoY0TFO6Wpo1UGClqeW4l/qd5SCIs10= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UYYq5QNT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="UYYq5QNT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7ED60C116D0; Wed, 25 Feb 2026 01:39:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771983541; bh=f7zn+o0yNYBYTvjzEMTzJIyybZ8kv2Q14Cn3yIyA/R4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UYYq5QNTQc4EujZVNgM5KuLRhK1U90Hq6rMyocMZ+pHT2bwHzO3tvLOzFzIV3JmUi 1UfiO+Z1icP4l9IgsipAWxHEZhbrJILAcN7mp5rWUa6PTPdRqE1vh7sLrmpLYs7F+2 uiTPXdRbH7gsXaprPGjtsZHrv7Xf23pMdL8mq9B4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daniel Machon , Maxime Chevallier , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.19 645/781] net: sparx5/lan969x: fix PTP clock max_adj value Date: Tue, 24 Feb 2026 17:22:34 -0800 Message-ID: <20260225012415.617846390@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260225012359.695468795@linuxfoundation.org> References: <20260225012359.695468795@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Machon [ Upstream commit a49d2a2c37a6252c41cbdd505f9d1c58d5a3817a ] The max_adj field in ptp_clock_info tells userspace how much the PHC clock frequency can be adjusted. ptp4l reads this and will never request a correction larger than max_adj. On both sparx5 and lan969x the clock offset may never converge because the servo needs a frequency correction larger than the current max_adj of 200000 (200 ppm) allows. The servo rails at the max and the offset stays in the tens of microseconds. The hardware has no inherent max adjustment limit; frequency correction is done by writing a 64-bit clock period increment to CLK_PER_CFG, and the register has plenty of range. The 200000 value was just an overly conservative software limit. The max_adj is shared between sparx5 and lan969x, and the increased value is safe for both. Fix this by increasing max_adj to 10000000 (10000 ppm), giving the servo sufficient headroom. Fixes: 0933bd04047c ("net: sparx5: Add support for ptp clocks") Signed-off-by: Daniel Machon Reviewed-by: Maxime Chevallier Link: https://patch.msgid.link/20260212-sparx5-ptp-max-adj-v2-v1-1-06b200e50ce3@microchip.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/microchip/sparx5/sparx5_ptp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_ptp.c b/drivers/net/ethernet/microchip/sparx5/sparx5_ptp.c index 2f168700f63c1..8b2e07821a950 100644 --- a/drivers/net/ethernet/microchip/sparx5/sparx5_ptp.c +++ b/drivers/net/ethernet/microchip/sparx5/sparx5_ptp.c @@ -576,7 +576,7 @@ static int sparx5_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) static struct ptp_clock_info sparx5_ptp_clock_info = { .owner = THIS_MODULE, .name = "sparx5 ptp", - .max_adj = 200000, + .max_adj = 10000000, .gettime64 = sparx5_ptp_gettime64, .settime64 = sparx5_ptp_settime64, .adjtime = sparx5_ptp_adjtime, -- 2.51.0