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 C0EC0448D1A; Thu, 30 Jul 2026 16:10:45 +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=1785427846; cv=none; b=cnbTcBqrS+j3thEj1ZtjLbwlF4o30oegUNrg0HqGPzA3u+tcFV35YgARstTan+MPV9wAl+5Okqs/BVoue/QnLRsHCyRebWb5ZhlwZ7tAuGaIAuvGXbzlkdnP9UHJQLP/ByGbxy6A74I59YoRrVFxKDf3Q7sLau7QT5ajl8etDs4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785427846; c=relaxed/simple; bh=Rwh9pDrjlyovhDb+6Xui4rMr151Up8Uli3LNReLFs6Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T+HHcAn6TM9TmHd25ragLqenfVlNcXF2jDHAEiBjgZWTTgW3K2QY0BZEPn1wiSpkwXLjzZcrDK05La1NJXbhTiee06TOvhOV386KxCjyfXCP/qlXcIy5Qa0Oa1M92SCm4ZEEnE1SapGUXcNbucrJQRrzYgOqrlE8m5V6f+cu3NM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mIFlu1Ic; 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="mIFlu1Ic" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 289CC1F000E9; Thu, 30 Jul 2026 16:10:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785427845; bh=zrTz9yUT6QDmAjJ9DBinOcADPLaDOgL1NsWHCkj9Zcg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mIFlu1IcAClD6hfWKwTIwH67Hmdx8UZVG7QjlIBavfG+zVNJt0TfJYRmbItAyb1Uc nG1lsc9iCOiMwKU0SFG6b9T1agDEfz7A4OhAs5rYjGAwtamxXuAudLRw+cnkF5boBu r+iX31JeCr2jy+9SOJuFh66R2UlLH5hAaS0/pYKs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, MinJea Kim Subject: [PATCH 6.6 277/484] staging: rtl8723bs: fix inverted HT40 secondary channel offset Date: Thu, 30 Jul 2026 16:12:54 +0200 Message-ID: <20260730141429.510882700@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141423.392222816@linuxfoundation.org> References: <20260730141423.392222816@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 6.6-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 @@ -1967,7 +1967,7 @@ 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;