[PATCH 6.1 226/609] staging: rtl8723bs: fix inverted HT40 secondary channel offset
Greg Kroah-Hartman <[email protected]>
| Newsgroups | org.kernel.vger.stable,dev.linux.lists.patches |
|---|---|
| Message-ID | <[email protected]> |
6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: MinJea Kim <[email protected]> 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: [email protected] Assisted-by: Claude-Code:claude-fable-5 bpftrace Signed-off-by: MinJea Kim <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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 @@ -1999,7 +1999,7 @@ 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;