> -----Original Message-----
> From: Martin Kaistra <martin.kaistra@xxxxxxxxxxxxx>
> Sent: Monday, January 8, 2024 7:11 PM
> To: linux-wireless@xxxxxxxxxxxxxxx
> Cc: Jes Sorensen <Jes.Sorensen@xxxxxxxxx>; Kalle Valo <kvalo@xxxxxxxxxx>; Ping-Ke Shih
> <pkshih@xxxxxxxxxxx>; Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx>; Sebastian Andrzej Siewior
> <bigeasy@xxxxxxxxxxxxx>
> Subject: [PATCH] wifi: rtl8xxxu: enable channel switch support
>
> The CSA countdown in the beacon frames, which are sent out by firmware,
> needs to get updated by the driver. Do this at the end of the
> update_beacon_work function by sleeping for a bit shorter than the
> beacon interval and then either scheduling another run of
> update_beacon_work or calling ieee80211_csa_finish() when the end of the
> countdown is reached.
>
> Signed-off-by: Martin Kaistra <martin.kaistra@xxxxxxxxxxxxx>
> ---
> .../net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> index 5fddbd6594a24..c4f3f52bde303 100644
> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> @@ -5696,7 +5696,7 @@ static void rtl8xxxu_send_beacon_frame(struct ieee80211_hw *hw,
> struct rtl8xxxu_priv *priv = hw->priv;
> struct sk_buff *skb = ieee80211_beacon_get(hw, vif, 0);
> struct device *dev = &priv->udev->dev;
> - int retry;
> + int retry, interval;
> u8 val8;
>
> /* BCN_VALID, write 1 to clear, cleared by SW */
> @@ -5722,6 +5722,15 @@ static void rtl8xxxu_send_beacon_frame(struct ieee80211_hw *hw,
>
> if (!retry)
> dev_err(dev, "%s: Failed to read beacon valid bit\n", __func__);
> +
> + if (vif->bss_conf.csa_active) {
> + interval = 1024 * vif->bss_conf.beacon_int;
> + usleep_range(interval - 2048, interval - 1024);
Can we use a delayed work? And, re-schedule it as early as possible to execute
this function in accurate interval of beacon_int, otherwise processing time of
this function will be accumulated.
> + if (ieee80211_beacon_cntdwn_is_complete(vif))
> + ieee80211_csa_finish(vif);
> + else
> + schedule_work(&priv->update_beacon_work);
> + }
> }
>
