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 473941A5BA0; Wed, 4 Jun 2025 01:06:30 +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=1748999190; cv=none; b=u5qQaORev7a6tnHpGQz/v5rImrhbrlXPIq6u64OyHq19yXPTzBlNReD7lnV//Glk7P9azR7owHvA50WosGRk4o2UcZs7mE6m3XOkxinbbD3vFtkyMsEqbJ/TQgvf428TXnyD1SQ5IyG04BurAhlyisPhW79NnY91vJChQLWTRek= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748999190; c=relaxed/simple; bh=q7JYVPVG2dRLlDqWkJSfnGRBlhdWxwq+TInUPdY3o64=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=PFvF4I9ePmimsRJ+UVPqN5JbhG0/yQhQYtv2uXdXq14x04hbBzjFz4bgDja6A7A4+IsnBsESWhOlx0Qqy2hyeHIg2b90CiHtzcx+cWa/YKiEQaqtSf4HjuU+nIjdTkcNghmRb7BOiRlGHK4TjCHHsnhZWFafFfQ22PKD6kMTLKk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GMhwNPq3; 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="GMhwNPq3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6662C4CEEF; Wed, 4 Jun 2025 01:06:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748999190; bh=q7JYVPVG2dRLlDqWkJSfnGRBlhdWxwq+TInUPdY3o64=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GMhwNPq3YNTYhv8Edqq4LTeDb5E92FsdNtPzGxUO+/DpiROetHGS1FIBfB+Z8Ptum +/+pKCgxQ36t04fYQdCxA3ANLFO/gv5E63Nk78mwRyYVp21lCvbin1IlaQ4jD7709q +Om8Itk2jsTobJOHme2LUUujE0647HmtXLQ4u8uFMT7aH5o/RTU69+CcUJ1cbsJUZ5 /O0C1VwfF6zzUSmztrDfa1LHVib+la3ckx/UhP7/TsiJfeRdXuOyyeFxWXKhljxnOh Fx9WphGcxFx1LCJomQ40KsZlEZo6g0u/NaTW6EOtf+FQMSVXTviCcgwlviIDs2lmRB gx5tSML0hQPMw== 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 5.10 05/27] wifi: mt76: mt76x2: Add support for LiteOn WN4516R,WN4519R Date: Tue, 3 Jun 2025 21:05:58 -0400 Message-Id: <20250604010620.6819-5-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250604010620.6819-1-sashal@kernel.org> References: <20250604010620.6819-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.237 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 82a193aac09d7..95c548f45bdf8 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, 0x9053) }, /* Netgear A6210 */ { USB_DEVICE(0x045e, 0x02e6) }, /* XBox One Wireless Adapter */ diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/usb_init.c b/drivers/net/wireless/mediatek/mt76/mt76x2/usb_init.c index ffc2deba29ac6..c845e83897659 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); @@ -215,7 +216,17 @@ 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