From nobody Mon Feb 9 13:59:29 2026 Received: from sg-1-101.ptr.blmpb.com (sg-1-101.ptr.blmpb.com [118.26.132.101]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 30B963F23C7 for ; Thu, 8 Jan 2026 10:18:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=118.26.132.101 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767867534; cv=none; b=QOs/d8ZROPsLwUKwQ9+ZGcmLO59hettbxeSsC659Zj7RhP0zYkSxFwTpbdX8MSrxyehb51WW/LfwDZYFm0zpxjsM1g6iqwjpgeIyu2ElWXk1LaE6hiewPlfJpTzWKE3ek8Dbhh4Qbq5XuY49bnsu5UY/1wSqmK7rGyL2O0ys6jA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767867534; c=relaxed/simple; bh=JZ3g6PRNm24rcwaSJzuaTWVXlS0Oz7zyfnO5GVwym2E=; h=Subject:Date:Message-Id:Mime-Version:From:Content-Type:To; b=EhZV+s3hUmbUDT1PHkqCVnZpurSvivq1aq0d0JneW08REZ5bPL+8OiGsRKuYjrBw3kz2XF6LQGeG6iIjvhIk/D7UzS4glJh8Dg/RKu+sZTpW2WOkzDZUoohAu+m229n+KGbLpYM0LBAI049dWC/miurVFzz74fIP84LHKXK7Byk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com; spf=pass smtp.mailfrom=bytedance.com; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b=UIO6CaEs; arc=none smtp.client-ip=118.26.132.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bytedance.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="UIO6CaEs" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=2212171451; d=bytedance.com; t=1767867523; h=from:subject: mime-version:from:date:message-id:subject:to:cc:reply-to:content-type: mime-version:in-reply-to:message-id; bh=EELGF/QRlwwwrX0driH/TLyxb0FIIjjfOwxxpl8bL5M=; b=UIO6CaEseM7KliEK6hr1De4tY55ZZa1SCfvXReqYA04W3vmSwW+zwIPR6z2ZQoFRt+Uw8d gS3kdVD7sK+OTaqZudD5c3AFUMe9zTJV6x2Tdl0/JdbsMUngyEcoViHdca2E1hDNispxue uh5YOcq6o8FUiVZjpXokdOoYrL16D5BtG/yACGtxOwJLoZ7GIzvkzSwoemdl6SROZqfgE1 S/JRoLmihKec6RMtd4dcuQGIfnK7hfAxuyfpVjCbzoasCwU2rPES4ZpUXnrphdVd/jfD5P VezvccQahkC18CYORik0dK6xtFnlfXkyjA7FLxMOgTLThcYWqwerYOVGHMoANg== Subject: [PATCH] net: mctp-i2c: fix duplicate reception of old data Date: Thu, 8 Jan 2026 18:18:29 +0800 Message-Id: <20260108101829.1140448-1-zhangjian.3032@bytedance.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Mailer: git-send-email 2.20.1 From: "Jian Zhang" X-Original-From: Jian Zhang X-Lms-Return-Path: To: "Jeremy Kerr" , "Matt Johnston" , "Andrew Lunn" , "David S. Miller" , "Eric Dumazet" , "Jakub Kicinski" , "Paolo Abeni" , , Content-Type: text/plain; charset="utf-8" The MCTP I2C slave callback did not handle I2C_SLAVE_READ_REQUESTED events. As a result, i2c read event will trigger repeated reception of old data, reset rx_pos when a read request is received. Signed-off-by: Jian Zhang --- drivers/net/mctp/mctp-i2c.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/mctp/mctp-i2c.c b/drivers/net/mctp/mctp-i2c.c index f782d93f826e..ecda1cc36391 100644 --- a/drivers/net/mctp/mctp-i2c.c +++ b/drivers/net/mctp/mctp-i2c.c @@ -242,6 +242,9 @@ static int mctp_i2c_slave_cb(struct i2c_client *client, return 0; =20 switch (event) { + case I2C_SLAVE_READ_REQUESTED: + midev->rx_pos =3D 0; + break; case I2C_SLAVE_WRITE_RECEIVED: if (midev->rx_pos < MCTP_I2C_BUFSZ) { midev->rx_buffer[midev->rx_pos] =3D *val; @@ -279,6 +282,9 @@ static int mctp_i2c_recv(struct mctp_i2c_dev *midev) size_t recvlen; int status; =20 + if (midev->rx_pos =3D=3D 0) + return 0; + /* + 1 for the PEC */ if (midev->rx_pos < MCTP_I2C_MINLEN + 1) { ndev->stats.rx_length_errors++; --=20 2.20.1