From mboxrd@z Thu Jan 1 00:00:00 1970 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 AB1073C2D; Sat, 14 Feb 2026 21:25:19 +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=1771104319; cv=none; b=qeZ3eTSvOXHcxSsgpeBeq7jVN7HGTk1SMbOYVTU6W9muZq5DLcUKnSWp5YShPagsp6TwRwJs7pa6nwmwmYXw/TlS8Z8yrck9Vcz2vZ6PjKMlBKlfYIfU1L0emuGP/YaUbTvi8Fmc1So62uBPLIMS4QMzVe21hCQ2d/b4WeZP24c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771104319; c=relaxed/simple; bh=SYr2jZH/JP9Q2+T65btHGzZV/xMCQcU2k3NTQZNlZYo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=i9l46Uo8O1Jc9LjizRE6eDTt2D+I3LHG2gb8VWeybHFEwtxFN+xe4/PMe2mQ2bIV0QE48SU5n8/vxq7bFPynt062p7gztE8iywidWLxQhUZ6LjuGlqYGk6Y37BU9XgaQIsC8PM56ZKv2a6M56hG2I9EmTekHUZGseX3N1zJAAS8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jOSOAlch; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jOSOAlch" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9948C16AAE; Sat, 14 Feb 2026 21:25:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771104319; bh=SYr2jZH/JP9Q2+T65btHGzZV/xMCQcU2k3NTQZNlZYo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jOSOAlchxPkQsgbn//peqQenf9TNeqzgjGmjfjqUJt5TEy6MaVk+XG/R18x9sdEHP PcdLnpcRb/odVkhmd5bSyKXwp5S682fVl+G7bbTIotNfZXFdYP8SZVmeHH/ZkqVM/h VjilcQkMmEkLtlqBFBxwqpFrutEXCWEJNVMeLBlmXOHTBB5xwEtjlu4nP3IWYLNV9o E8TOtmI1HeAJtMe+Ldz17ekoDSSFKMuIzG5/kxZZXoSCDb3j4yiGLtg5ZcUXvswZq+ jqJKCpQn3nSv5I5CzlIP/ZI3Z6MLXan4x34qNKw2K81Xy3Gb5hpDDAUwvdf7/06lcL XN5MrqgsgeP0w== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Slark Xiao , Jakub Kicinski , Sasha Levin , loic.poulain@oss.qualcomm.com, ryazanov.s.a@gmail.com, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 6.19-6.12] net: wwan: mhi: Add network support for Foxconn T99W760 Date: Sat, 14 Feb 2026 16:22:39 -0500 Message-ID: <20260214212452.782265-14-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260214212452.782265-1-sashal@kernel.org> References: <20260214212452.782265-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.19 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Slark Xiao [ Upstream commit 915a5f60ad947e8dd515d2cc77a96a14dffb3f15 ] T99W760 is designed based on Qualcomm SDX35 chip. It use similar architecture with SDX72/SDX75 chip. So we need to assign initial link id for this device to make sure network available. Signed-off-by: Slark Xiao Link: https://patch.msgid.link/20260105022646.10630-1-slark_xiao@163.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: ## Analysis ### Commit Message Analysis The commit adds network support for a new device, the Foxconn T99W760, which is based on the Qualcomm SDX35 chip. The commit message explains that this device uses a similar architecture to SDX72/SDX75 and needs an initial link ID assignment to make networking functional. ### Code Change Analysis The change is extremely minimal — a single line addition: ```c strcmp(cntrl->name, "foxconn-t99w760") == 0) ``` This adds the "foxconn-t99w760" device name to the `mhi_mbim_get_link_mux_id()` function so that it returns `WDS_BIND_MUX_DATA_PORT_MUX_ID` instead of `0`. This is the same treatment already given to "foxconn-dw5934e" and "foxconn-t99w640". ### Classification: Device ID / Hardware Enablement This falls squarely into the **"New Device IDs"** exception category for stable backports. It's adding support for a specific device to an existing driver by matching its name and applying the same configuration that other similar devices already use. Without this change, users with the Foxconn T99W760 WWAN modem cannot use networking — the device gets the wrong mux ID (0 instead of `WDS_BIND_MUX_DATA_PORT_MUX_ID`), making the network interface non- functional. ### Risk Assessment - **Scope**: 1 line added, 1 file changed - **Risk**: Extremely low — the change only affects devices matching the exact name "foxconn-t99w760". No other hardware is affected. - **Pattern**: Follows the exact same pattern as existing devices in the same function - **Complexity**: Trivial string comparison addition ### User Impact Users with the Foxconn T99W760 WWAN modem (a real shipping hardware device) cannot use network connectivity without this patch. This is a real-world hardware enablement fix. ### Stability Assessment - The driver (`mhi_wwan_mbim.c`) already exists in stable trees - The function `mhi_mbim_get_link_mux_id()` already exists - The pattern is identical to existing entries - Zero risk of regression for any other hardware ### Dependencies No dependencies on other commits. The change is entirely self-contained. ### Conclusion This is a textbook device ID addition to an existing driver — one of the explicitly allowed exception categories for stable backports. It enables real hardware for real users, is trivially small, has zero regression risk, and follows an established pattern in the same function. **YES** drivers/net/wwan/mhi_wwan_mbim.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wwan/mhi_wwan_mbim.c b/drivers/net/wwan/mhi_wwan_mbim.c index f8bc9a39bfa30..1d7e3ad900c12 100644 --- a/drivers/net/wwan/mhi_wwan_mbim.c +++ b/drivers/net/wwan/mhi_wwan_mbim.c @@ -98,7 +98,8 @@ static struct mhi_mbim_link *mhi_mbim_get_link_rcu(struct mhi_mbim_context *mbim static int mhi_mbim_get_link_mux_id(struct mhi_controller *cntrl) { if (strcmp(cntrl->name, "foxconn-dw5934e") == 0 || - strcmp(cntrl->name, "foxconn-t99w640") == 0) + strcmp(cntrl->name, "foxconn-t99w640") == 0 || + strcmp(cntrl->name, "foxconn-t99w760") == 0) return WDS_BIND_MUX_DATA_PORT_MUX_ID; return 0; -- 2.51.0