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From: Ping-Ke Shih <pkshih@realtek.com>
To: Martin Kaistra <martin.kaistra@linutronix.de>,
        "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
CC: Jes Sorensen <Jes.Sorensen@gmail.com>, Kalle Valo <kvalo@kernel.org>,
        Bitterblue Smith <rtl8821cerfe2@gmail.com>,
        Sebastian Andrzej Siewior
	<bigeasy@linutronix.de>
Subject: RE: [PATCH] wifi: rtl8xxxu: enable channel switch support
Thread-Topic: [PATCH] wifi: rtl8xxxu: enable channel switch support
Thread-Index: AQHaQiODHEhpK9S3y0SNBT3W3hf7YbDQzGgg
Date: Tue, 9 Jan 2024 03:14:15 +0000
Message-ID: <3bc29348011242789a7ba1c2883d9b3a@realtek.com>
References: <20240108111103.121378-1-martin.kaistra@linutronix.de>
In-Reply-To: <20240108111103.121378-1-martin.kaistra@linutronix.de>
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> -----Original Message-----
> From: Martin Kaistra <martin.kaistra@linutronix.de>
> Sent: Monday, January 8, 2024 7:11 PM
> To: linux-wireless@vger.kernel.org
> Cc: Jes Sorensen <Jes.Sorensen@gmail.com>; Kalle Valo <kvalo@kernel.org>;=
 Ping-Ke Shih
> <pkshih@realtek.com>; Bitterblue Smith <rtl8821cerfe2@gmail.com>; Sebasti=
an Andrzej Siewior
> <bigeasy@linutronix.de>
> Subject: [PATCH] wifi: rtl8xxxu: enable channel switch support
>=20
> 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.
>=20
> Signed-off-by: Martin Kaistra <martin.kaistra@linutronix.de>
> ---
>  .../net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c   | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
>=20
> 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 ieee8=
0211_hw *hw,
>         struct rtl8xxxu_priv *priv =3D hw->priv;
>         struct sk_buff *skb =3D ieee80211_beacon_get(hw, vif, 0);
>         struct device *dev =3D &priv->udev->dev;
> -       int retry;
> +       int retry, interval;
>         u8 val8;
>=20
>         /* BCN_VALID, write 1 to clear, cleared by SW */
> @@ -5722,6 +5722,15 @@ static void rtl8xxxu_send_beacon_frame(struct ieee=
80211_hw *hw,
>=20
>         if (!retry)
>                 dev_err(dev, "%s: Failed to read beacon valid bit\n", __f=
unc__);
> +
> +       if (vif->bss_conf.csa_active) {
> +               interval =3D 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 exec=
ute
this function in accurate interval of beacon_int, otherwise processing time=
 of
this function will be accumulated.=20

> +               if (ieee80211_beacon_cntdwn_is_complete(vif))
> +                       ieee80211_csa_finish(vif);
> +               else
> +                       schedule_work(&priv->update_beacon_work);
> +       }
>  }
>=20