On 2020-05-18 16:14:44 [+0800], yhchuang@xxxxxxxxxxx wrote:
> From: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
>
> If we connect to an AP with WPA2 security, the IQK and the
> EAPOL 4-way handshake may be failed due to overlap, because
> driver does IQK right after assoc success.
Connectig to an AP with WPA2 security may fail. The IQK and the EAPOL
4-way handshake may overlap because the driver does IQK right after
assoc success.
> For 802.11n devices, they used to do IQK in driver that could
> requires more than 100ms to finished. During IQK, any TX/RX
> events are paused. So, if the EAPOL 4-way started before IQK
> is finished, the 1/4 and 2/4 could be dropped, then the AP
> will issue deauth with reason IEEE8021X_FAILED (23).
For 802.11n devices the IQK is done in the driver and could
require more than 100ms to complete. During IQK any TX/RX
events are paused. So if the EAPOL 4-way handshake started before
IQK finished then the 1/4 and 2/4 part of the handshake could be dropped.
The AP will then issue deauth with reason IEEE8021X_FAILED (23).
> To resolve this, move IQK routine into managed TX prepare,
> which is ieee80211_ops::mgd_prepare_tx() called before the
> managed frames (auth/assoc) are sent. This can make sure IQK
> is done before connection. While scanning, not to do IQK for
> each channel because it would take too long.
To resolve this move IQK routine into managed TX prepare
(ieee80211_ops::mgd_prepare_tx()). The callback is called
before the managed frames (auth/assoc) are sent. This will make
sure that IQK is completed before the handshake starts.
Don't do IQK during scanning because doing it each channel ill take
too long.
> For 802.11ac devices, they used to do IQK in firmware, and it
> takes less time to finish it, so we do not see EAPOL 4-way
> failure on them. But, it is still worth to move the IQK to
> mgd_prepare_tx().
The 802.11ac devices do IQK in firmware and it takes less time to
complete. Therefore we don't see a failure during the EAPOL 4-way
handshake. It is still worth IQK to ieee80211_ops::mgd_prepare_tx().
> Fixes: f5df1a8b4376 ("rtw88: 8723d: Add 8723DE to Kconfig and Makefile")
> Signed-off-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
> Signed-off-by: Yan-Hsuan Chuang <yhchuang@xxxxxxxxxxx>
> ---
> drivers/net/wireless/realtek/rtw88/mac80211.c | 3 +--
> drivers/net/wireless/realtek/rtw88/main.c | 16 ++++++++++++++++
> drivers/net/wireless/realtek/rtw88/main.h | 3 +++
> 3 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/realtek/rtw88/mac80211.c b/drivers/net/wireless/realtek/rtw88/mac80211.c
> index 98d2ac22f6f6..c412bc54efde 100644
> --- a/drivers/net/wireless/realtek/rtw88/mac80211.c
> +++ b/drivers/net/wireless/realtek/rtw88/mac80211.c
> @@ -341,13 +341,11 @@ static void rtw_ops_bss_info_changed(struct ieee80211_hw *hw,
> rtw_leave_lps_deep(rtwdev);
>
> if (changed & BSS_CHANGED_ASSOC) {
> - struct rtw_chip_info *chip = rtwdev->chip;
> enum rtw_net_type net_type;
>
> if (conf->assoc) {
> rtw_coex_connect_notify(rtwdev, COEX_ASSOCIATE_FINISH);
> net_type = RTW_NET_MGD_LINKED;
> - chip->ops->phy_calibration(rtwdev);
>
> rtwvif->aid = conf->aid;
> rtw_fw_download_rsvd_page(rtwdev);
> @@ -663,6 +661,7 @@ static void rtw_ops_mgd_prepare_tx(struct ieee80211_hw *hw,
> mutex_lock(&rtwdev->mutex);
> rtw_leave_lps_deep(rtwdev);
> rtw_coex_connect_notify(rtwdev, COEX_ASSOCIATE_START);
> + rtw_chip_prepare_tx(rtwdev);
> mutex_unlock(&rtwdev->mutex);
> }
>
> diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
> index f88a7d2370aa..d561968b67da 100644
> --- a/drivers/net/wireless/realtek/rtw88/main.c
> +++ b/drivers/net/wireless/realtek/rtw88/main.c
> @@ -408,6 +408,22 @@ void rtw_set_channel(struct rtw_dev *rtwdev)
> }
>
> rtw_phy_set_tx_power_level(rtwdev, center_chan);
> +
> + /* If set channel isn't for scanning, we'll do RF calibration once in
> + * this channel while mgd_prepare_tx.
> + */
/* If the channel isn't set for scanning, we'll do RF calibration
* in ::mgd_prepare_tx(). Performing the calibration during
* scanning on each channel takes too long.
*/
> + if (!test_bit(RTW_FLAG_SCANNING, rtwdev->flags))
> + rtwdev->need_rfk = true;
> +}
> +
> +void rtw_chip_prepare_tx(struct rtw_dev *rtwdev)
> +{
> + struct rtw_chip_info *chip = rtwdev->chip;
> +
> + if (rtwdev->need_rfk) {
> + rtwdev->need_rfk = false;
> + chip->ops->phy_calibration(rtwdev);
> + }
> }
Sebastian
