From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7C04938DC50; Thu, 30 Jul 2026 14:48:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785422919; cv=none; b=DZ7b2XI4M8vOJ4oVXLKIwtDbaVtrmElHXDkJPAURaV80PwPdY0Tx80ySj+NV/OXNetNA78fXLwV65aphGGrkqZr1/1dEdeZjrC31h/Svvl/I3L3ieAVks0cX2UTw3ylGKu8QuQpNUKLKCIUv9h9HRw1kEfVEPPykDF4qqe7bnd8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785422919; c=relaxed/simple; bh=zkT8olvV4478eG7s7gKskc9Og5mOmtiHmbMmt1iPLC8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Akvs4M9I92NintWNloo+/A+omJQMBd7SqMoA2dnde7RZnwublqgRbqLb4NzX8dGr622PtA2ReSCAvguaYHTbmv4l1ZvQhuydhKEzYjsya3zaLP+JjrXU1nRhI6QLBCip8k24m6U592XTKFNC/XD7IMtvICL74Go5MTHHBSRfM/Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=f+mkzO8R; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="f+mkzO8R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7DAE1F000E9; Thu, 30 Jul 2026 14:48:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785422918; bh=5R+0KNz2ppXdLZqppq3TjywntgazohIDOu+5+Q6z8BA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=f+mkzO8RwEZTPegIQhOTGva/Bb+/EeQ8p9UDl/VABCFJ2aRbI2QAaHUU/oOaSl8NJ lP5fLMFUGfaEjBTiKZ5QJWZh11W/kw0WOtIQJNGaV1xijoTiqqn9v4Z3DSSnXv8T2A jmaRcqTlb9ewCJOuqmj4MnDLFYuqjl+AOzaBAbtA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, MinJea Kim Subject: [PATCH 7.1 557/744] staging: rtl8723bs: fix inverted HT40 secondary channel offset Date: Thu, 30 Jul 2026 16:13:50 +0200 Message-ID: <20260730141456.120441679@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141444.267951807@linuxfoundation.org> References: <20260730141444.267951807@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: MinJea Kim commit 30d49cba27f8905bc288cef5846963f0004f644c upstream. rtw_get_chan_type() maps the driver's channel offset to nl80211 channel types the wrong way around. In this driver HAL_PRIME_CHNL_OFFSET_LOWER means the primary channel is the lower 20 MHz half of the 40 MHz pair, i.e. the secondary channel is above the primary one: rtw_get_center_ch() computes the center channel as "channel + 2" for OFFSET_LOWER, and bwmode_update_check() sets OFFSET_LOWER when the AP's HT operation IE announces SCA (secondary channel above). In nl80211 terms that is NL80211_CHAN_HT40PLUS, not HT40MINUS. Because of the inversion, cfg80211_rtw_get_channel() reports an HT40+ association as HT40-. For an HT40+ AP on a low channel (e.g. channel 3) the resulting chandef spans below the 2.4 GHz band edge and is invalid, so the regulatory core tears the connection down 60 seconds (REG_ENFORCE_GRACE_MS) after the AP's country IE triggers a regdomain change: reg_check_chans_work() considers the reported chandef unusable and calls cfg80211_leave(). The supplicant then reconnects, the country IE changes the regdomain again, and the cycle repeats, causing a disconnect/reconnect loop every ~65 seconds for as long as the link is up. Observed on a TECLAST X80 Power tablet (RTL8723BS) associated to an HT40+ AP on channel 3 with a KR country IE; a kprobe trace showed cfg80211_disconnect() being invoked from reg_check_chans_work(). With the mapping fixed, "iw dev wlan0 info" reports the correct "width: 40 MHz, center1: 2432 MHz" and the periodic disconnects stop. Fixes: 5402cc178c5d ("staging: rtl8723bs: add get_channel cfg80211 implementation") Cc: stable@vger.kernel.org Assisted-by: Claude-Code:claude-fable-5 bpftrace Signed-off-by: MinJea Kim Link: https://patch.msgid.link/20260714131421.3980-1-qndkdrnl@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c +++ b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c @@ -1956,7 +1956,7 @@ static u8 rtw_get_chan_type(struct adapt else return NL80211_CHAN_NO_HT; case CHANNEL_WIDTH_40: - if (mlme_ext->cur_ch_offset == HAL_PRIME_CHNL_OFFSET_UPPER) + if (mlme_ext->cur_ch_offset == HAL_PRIME_CHNL_OFFSET_LOWER) return NL80211_CHAN_HT40PLUS; else return NL80211_CHAN_HT40MINUS;