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 2AF449478; Mon, 25 Aug 2025 12:15:08 +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=1756124109; cv=none; b=odE2zcTN2YN/XuF5nnc4iMlsKdh0h5SnvSoV93sOsBXoXwCGaxZR/bg+Eo4MPO23KZd2zu8iHvP0lv61hbjOy2yA60ze3cVSuaM3dZzc71Wom3BZcksIPPBWzRvIEoeGdjdfEar/7f09f+ghJrazfIDffdYYEQlYmAHG4PSx4nY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756124109; c=relaxed/simple; bh=alL0tPmHLDm5NA77251sOI6jBFp6e0bCu3oKZ1m9NgA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=nh9NtzHlyVHecNzmc9bnA7Xjcqi6l3qEIcv+hGajcHxwodCODLiDBJjZKQm1ZoKVgn3FD/LhsauwSYMKtOGdJmZhqTIjTCXkAwRD0K8gQp4xdoJFQqbEN+fvVwcdnfIIet01qtgkj2Dkb5D9dHUEXoThU9WmmRn6EbPjeQyKOhY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=s1pOUzQH; 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="s1pOUzQH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDADDC116B1; Mon, 25 Aug 2025 12:15:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756124108; bh=alL0tPmHLDm5NA77251sOI6jBFp6e0bCu3oKZ1m9NgA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=s1pOUzQHV6wUhy1er26yz/7G7BNYQj9jWP1/WWRQnaJTnD2GqLh/uV1JYUZFEoBx4 VMkjGOBmCuFcu7rC0vbugF7rlV7GNWYPK3b16CWfCKzVUNhhbuhG3uyGFTwUDVctEq oJxLmJ7zxtyVKQx0pWjdcx3k8TvyAbdKQiJFfNS0zP9sXj27MwM2Kg5OsBz+8h9h6U 1XJ4JwIztW/efn9iDDL5tEjgw4B+cOoDzZ9WJzFgNd/qkiEYws/ExlG3Ps07H4qPtQ YZLZ/IBB8nivMn8O1NpwoFfgCWYBvQOr46njmuGWkJbFolbwYA1ZF9aBQKxEU4Su/p jv+FJpxuCSuIQ== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Lubomir Rintel , Jakub Kicinski , Sasha Levin , oliver@neukum.org, linux-usb@vger.kernel.org Subject: [PATCH AUTOSEL 6.16-6.1] cdc_ncm: Flag Intel OEM version of Fibocom L850-GL as WWAN Date: Mon, 25 Aug 2025 08:14:51 -0400 Message-ID: <20250825121505.2983941-2-sashal@kernel.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250825121505.2983941-1-sashal@kernel.org> References: <20250825121505.2983941-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.16.3 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Lubomir Rintel [ Upstream commit 4a73a36cb704813f588af13d9842d0ba5a185758 ] This lets NetworkManager/ModemManager know that this is a modem and needs to be connected first. Signed-off-by: Lubomir Rintel Link: https://patch.msgid.link/20250814154214.250103-1-lkundrak@v3.sk Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: **Backport Status: YES** This commit should be backported to stable kernel trees for the following reasons: ## Analysis of the Commit: 1. **Nature of the change**: This is a simple device ID addition that adds USB vendor/device ID pair (0x8087:0x095a) for the Intel OEM version of Fibocom L850-GL modem to the cdc_ncm driver's device table. 2. **Bug fix vs feature**: This is a **hardware enablement fix** rather than a new feature. Without this change, the Intel-branded Fibocom L850-GL modem won't be properly recognized as a WWAN device, causing NetworkManager/ModemManager to fail to handle it correctly. This directly impacts users with this hardware. 3. **Code impact**: The change is minimal - just 7 lines adding a new entry to the `cdc_devs[]` USB device table: ```c /* Intel modem (label from OEM reads Fibocom L850-GL) */ { USB_DEVICE_AND_INTERFACE_INFO(0x8087, 0x095a, USB_CLASS_COMM, USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE), .driver_info = (unsigned long)&wwan_info, }, ``` 4. **Risk assessment**: - **Extremely low risk** - The change only adds a new device ID entry - No existing functionality is modified - Uses the existing `wwan_info` driver configuration (FLAG_WWAN flag) - Follows the same pattern as other WWAN devices in the driver - Cannot cause regressions for other hardware 5. **User impact**: Users with this specific hardware (Intel OEM version with VID:PID 0x8087:0x095a) cannot use their modem properly without this fix. The modem won't be recognized as a WWAN device, preventing proper network management. 6. **Stable tree criteria compliance**: - ✓ Fixes a real bug (hardware not working properly) - ✓ Minimal change (7 lines) - ✓ No architectural changes - ✓ Self-contained to specific hardware - ✓ Clear and obvious correctness 7. **Historical context**: The git history shows numerous quirks and fixes for the Fibocom L850-GL modem variants, indicating this is well-known hardware that has required various fixes over time. This particular Intel OEM variant (0x8087:0x095a) was simply missing from the device table. This is a textbook example of a stable-worthy commit: it enables specific hardware that should already be working, with zero risk to existing functionality. drivers/net/usb/cdc_ncm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index ea0e5e276cd6..5d123df0a866 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -2087,6 +2087,13 @@ static const struct usb_device_id cdc_devs[] = { .driver_info = (unsigned long)&wwan_info, }, + /* Intel modem (label from OEM reads Fibocom L850-GL) */ + { USB_DEVICE_AND_INTERFACE_INFO(0x8087, 0x095a, + USB_CLASS_COMM, + USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE), + .driver_info = (unsigned long)&wwan_info, + }, + /* DisplayLink docking stations */ { .match_flags = USB_DEVICE_ID_MATCH_INT_INFO | USB_DEVICE_ID_MATCH_VENDOR, -- 2.50.1