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 C7DAB1E871; Wed, 4 Jun 2025 00:51:20 +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=1748998280; cv=none; b=QEuFrt1OUD67oMWp/TWB4FPwMSVBAi9tWZUZxV0ozsu7ACoGVhD+NoWl2FJXcSge12FjMQQSa7ls4mwA6VHM16lBv+D8KhHmnp5GuDrQ3C3LWpjPdzQnHfkU4PuzKjcghXQ8tKpSOcs+dUSxC14Iwq5G7xXqBgC1+Dofo/4yRQ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748998280; c=relaxed/simple; bh=NYSO8VsZ/0XDY2gTpPGIted5zwAYOW8Rxei3gMji5qo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=tU3nnK+keVRfMR+nYle3nBdq5ys04G59x78BaF27vgUOhaiNicgX6SgVdxHUk1Mcvcrkrob1BRt8aART+3fvhbwl6SSZ4JqWChKIAUjggLj6XDAE8KcOcNjoMU7oSxRRsRbO9kyFrAItiXG8LFngCB9YvJfM+4ImVRUkeYMRQjc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gaRGVo0n; 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="gaRGVo0n" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5556BC4CEED; Wed, 4 Jun 2025 00:51:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748998280; bh=NYSO8VsZ/0XDY2gTpPGIted5zwAYOW8Rxei3gMji5qo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gaRGVo0nC0ZHYrIFfxZ7Wy2o3+Oy8FePY4adqUogzeEakBK5s70K9ULWmdU1uV/No 2XCU9T/3j3wm0UYmR1FmhMxzn6Hf1CtZWHzXEWpFYaFTpm/4hB4SUKVeYWfxcQcsCU UHvHhAQSMkmLh0b9eAGAp9HuAas8VQerTfF9lkrSz3g7VWyQRzNwFI1vnuL6+IRCop x3e7ogNg+H5B9P9hhpkS9VrInnvJYD2G9YolFjZh3B/J0nvi4+5snxaBGUAOlcIvlt ToYrhX85RLt+1HV+TrgtPq2PCvgunOp03E4+ELTtCi3caU0IAi8W4Yr374hOgn3Czp sHHcTXLBrSSew== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Henk Vergonet , Lorenzo Bianconi , Felix Fietkau , Sasha Levin , matthias.bgg@gmail.com, angelogioacchino.delregno@collabora.com, uwu@icenowy.me, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH AUTOSEL 6.15 016/118] wifi: mt76: mt76x2: Add support for LiteOn WN4516R,WN4519R Date: Tue, 3 Jun 2025 20:49:07 -0400 Message-Id: <20250604005049.4147522-16-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250604005049.4147522-1-sashal@kernel.org> References: <20250604005049.4147522-1-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 6.15 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Henk Vergonet [ Upstream commit 3c0e4f606d8693795a2c965d6f4987b1bfc31097 ] Adds support for: - LiteOn WN4516R - LiteOn WN4519R Both use: - A nonstandard USB connector - Mediatek chipset MT7600U - ASIC revision: 76320044 Disabled VHT support on ASIC revision 76320044: This fixes the 5G connectibity issue on LiteOn WN4519R module see https://github.com/openwrt/mt76/issues/971 And may also fix the 5G issues on the XBox One Wireless Adapter see https://github.com/openwrt/mt76/issues/200 I have looked at the FCC info related to the MT7632U chip as mentioned in here: https://github.com/openwrt/mt76/issues/459 These confirm the chipset does not support 'ac' mode and hence VHT should be turned of. Signed-off-by: Henk Vergonet Acked-by: Lorenzo Bianconi Link: https://patch.msgid.link/20250418143914.31384-1-henk.vergonet@gmail.com Signed-off-by: Felix Fietkau Signed-off-by: Sasha Levin --- **YES** This commit should be backported to stable kernel trees. Here's my detailed analysis: ## Comparison with Similar Commits This commit closely matches **Similar Commit #1** (XBox One wifi adapter support) which was marked as **YES** for backporting. Both commits: - Add new USB device IDs for wireless adapters - Include hardware-specific workarounds for device limitations - Fix connectivity issues for specific hardware ## Code Changes Analysis ### 1. USB Device ID Additions (Low Risk) ```c { USB_DEVICE(0x0471, 0x2126) }, /bin /bin.usr-is-merged /boot /dev /etc /home /init /lib /lib.usr-is-merged /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /sbin.usr-is-merged /snap /srv /sys /tmp /usr /var LiteOn WN4516R module, nonstandard USB connector linux/ { USB_DEVICE(0x0471, 0x7600) }, /bin /bin.usr-is-merged /boot /dev /etc /home /init /lib /lib.usr-is-merged /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /sbin.usr-is-merged /snap /srv /sys /tmp /usr /var LiteOn WN4519R module, nonstandard USB connector linux/ ``` - **Risk**: Minimal - adding device IDs is very safe - **Impact**: Enables support for new hardware without affecting existing devices - **Scope**: Contained to device identification ### 2. VHT Capability Fix (Critical Bug Fix) ```c switch (dev->mt76.rev) { case 0x76320044: /bin /bin.usr- is-merged /boot /dev /etc /home /init /lib /lib.usr-is-merged /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /sbin.usr-is-merged /snap /srv /sys /tmp /usr /var these ASIC revisions do not support VHT linux/ vht = false; break; default: vht = true; break; } ``` - **Fixes critical connectivity issues**: The commit explicitly fixes 5G connectivity problems - **Hardware-specific workaround**: Targets a specific ASIC revision (0x76320044) - **Conservative approach**: Disables problematic VHT only for affected hardware - **Minimal regression risk**: Existing devices continue using VHT as before ## Backport Suitability Criteria ✅ **Fixes user-affecting bugs**: Resolves 5G connectivity issues on LiteOn modules and potentially XBox One adapters ✅ **Small and contained**: Changes are minimal - 2 new USB IDs and a targeted VHT disable ✅ **No architectural changes**: Uses existing framework, just adds device support and fixes capability detection ✅ **References external issues**: Links to GitHub issues #971 and #200, indicating real user problems ✅ **Clear side effects documentation**: VHT disabling is well-documented and justified with FCC information ✅ **Follows stable tree rules**: Important hardware support fix with minimal regression risk ✅ **Confined to subsystem**: Changes limited to mt76x2 USB driver ## Hardware Impact Assessment The commit addresses **confirmed hardware limitations** where VHT was incorrectly enabled on chipsets that don't support it, causing: - Connection failures in 5GHz band - Potential instability when VHT features are attempted This matches the pattern of **Similar Commit #1** which added support for newer XBox One adapters and was successfully backported. The risk/benefit ratio strongly favors backporting: minimal code changes that fix real connectivity issues for specific hardware without affecting other devices. drivers/net/wireless/mediatek/mt76/mt76x2/usb.c | 2 ++ .../net/wireless/mediatek/mt76/mt76x2/usb_init.c | 13 ++++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c b/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c index 84ef80ab4afbf..96cecc576a986 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c +++ b/drivers/net/wireless/mediatek/mt76/mt76x2/usb.c @@ -17,6 +17,8 @@ static const struct usb_device_id mt76x2u_device_table[] = { { USB_DEVICE(0x057c, 0x8503) }, /* Avm FRITZ!WLAN AC860 */ { USB_DEVICE(0x7392, 0xb711) }, /* Edimax EW 7722 UAC */ { USB_DEVICE(0x0e8d, 0x7632) }, /* HC-M7662BU1 */ + { USB_DEVICE(0x0471, 0x2126) }, /* LiteOn WN4516R module, nonstandard USB connector */ + { USB_DEVICE(0x0471, 0x7600) }, /* LiteOn WN4519R module, nonstandard USB connector */ { USB_DEVICE(0x2c4e, 0x0103) }, /* Mercury UD13 */ { USB_DEVICE(0x0846, 0x9014) }, /* Netgear WNDA3100v3 */ { USB_DEVICE(0x0846, 0x9053) }, /* Netgear A6210 */ diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/usb_init.c b/drivers/net/wireless/mediatek/mt76/mt76x2/usb_init.c index 33a14365ec9b9..3b55628115115 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76x2/usb_init.c +++ b/drivers/net/wireless/mediatek/mt76/mt76x2/usb_init.c @@ -191,6 +191,7 @@ int mt76x2u_register_device(struct mt76x02_dev *dev) { struct ieee80211_hw *hw = mt76_hw(dev); struct mt76_usb *usb = &dev->mt76.usb; + bool vht; int err; INIT_DELAYED_WORK(&dev->cal_work, mt76x2u_phy_calibrate); @@ -217,7 +218,17 @@ int mt76x2u_register_device(struct mt76x02_dev *dev) /* check hw sg support in order to enable AMSDU */ hw->max_tx_fragments = dev->mt76.usb.sg_en ? MT_TX_SG_MAX_SIZE : 1; - err = mt76_register_device(&dev->mt76, true, mt76x02_rates, + switch (dev->mt76.rev) { + case 0x76320044: + /* these ASIC revisions do not support VHT */ + vht = false; + break; + default: + vht = true; + break; + } + + err = mt76_register_device(&dev->mt76, vht, mt76x02_rates, ARRAY_SIZE(mt76x02_rates)); if (err) goto fail; -- 2.39.5