Re: [PATCH 05/19] wifi: rtw88: fw: send rate adaptation and RSSI info in the vendor layout

[Bitterblue Smith <rtl8821cerfe2@gmail.com>]

On 24/07/2026 21:18, luka.gejak@linux.dev wrote:
> From: Luka Gejak <luka.gejak@linux.dev>
> 
> The v41 firmware shipped with the RTL8723BS parses the vendor v5.2.17
> MACID_CFG and RA_INFO byte layouts rather than the bit packed rtw88
> ones, so the existing commands are misinterpreted and rate adaptation
> never settles.
> 
> Emit the byte layout the firmware expects for this chip. The no_update
> bit needs care: setting it tells the firmware to keep the rate mask it
> already has, so a changed mask sent with no_update set is silently
> dropped. Track the last mask sent and clear no_update whenever it
> actually changes, while leaving it set for identical refreshes so the
> firmware keeps the rate it has learned.
> 
> Signed-off-by: Luka Gejak <luka.gejak@linux.dev>
> ---
>  drivers/net/wireless/realtek/rtw88/fw.c   | 47 +++++++++++++++++++++--
>  drivers/net/wireless/realtek/rtw88/main.h |  2 +
>  2 files changed, 46 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtw88/fw.c b/drivers/net/wireless/realtek/rtw88/fw.c
> index a81ff15218e1..495d26eafdd4 100644
> --- a/drivers/net/wireless/realtek/rtw88/fw.c
> +++ b/drivers/net/wireless/realtek/rtw88/fw.c
> @@ -744,9 +744,19 @@ void rtw_fw_send_rssi_info(struct rtw_dev *rtwdev, struct rtw_sta_info *si)
>  
>  	SET_H2C_CMD_ID_CLASS(h2c_pkt, H2C_CMD_RSSI_MONITOR);
>  
> -	SET_RSSI_INFO_MACID(h2c_pkt, si->mac_id);
> -	SET_RSSI_INFO_RSSI(h2c_pkt, rssi);
> -	SET_RSSI_INFO_STBC(h2c_pkt, stbc_en);
> +	if (rtw_is_8723bs(rtwdev)) {
> +		/* Vendor v5.2.17 RA_INFO byte layout (H2C 0x42):
> +		 * [1] mac_id, [2] 0x00, [3] rssi, [4] stbc?0x04:0x00.
> +		 */
> +		h2c_pkt[1] = si->mac_id & 0x7f;
> +		h2c_pkt[2] = 0x00;
> +		h2c_pkt[3] = rssi;
> +		h2c_pkt[4] = stbc_en ? 0x04 : 0x00;

Not sure where you found the value 0x04. I see in hal/phydm/phydm_rssi_monitor.c
that it's setting bit 1, same as rtw88. The other bytes you set here
are equivalent to the macros in the else branch.

> +	} else {
> +		SET_RSSI_INFO_MACID(h2c_pkt, si->mac_id);
> +		SET_RSSI_INFO_RSSI(h2c_pkt, rssi);
> +		SET_RSSI_INFO_STBC(h2c_pkt, stbc_en);
> +	}
>  
>  	rtw_fw_send_h2c_command(rtwdev, h2c_pkt);
>  }
> @@ -760,6 +770,37 @@ void rtw_fw_send_ra_info(struct rtw_dev *rtwdev, struct rtw_sta_info *si,
>  
>  	SET_H2C_CMD_ID_CLASS(h2c_pkt, H2C_CMD_RA_INFO);
>  
> +	if (rtw_is_8723bs(rtwdev)) {
> +		/* The v41 firmware parses the vendor v5.2.17 MACID_CFG (0x40)
> +		 * byte layout, not the bit-packed rtw88 RA_INFO below:
> +		 * [1] mac_id, [2] rate_id | sgi_en(bit7),
> +		 * [3] bw(bits 1-0) | no_update(bit3), [4..7] 4-byte mask.
> +		 *
> +		 * no_update(bit3)=1 tells the firmware to keep its existing
> +		 * rate mask, so a mask that changes under no_update is dropped.
> +		 * Force no_update=0 whenever the mask actually changes so the
> +		 * update is applied, and keep no_update=1 for identical
> +		 * refreshes so the firmware retains the rate it has learned.
> +		 */
> +		bool apply = reset_ra_mask || si->ra_mask != si->ra_mask_last;

This doesn't look like the vendor driver's behaviour. To me it
looks like rtw88 is already handling the no_update bit correctly.

> +
> +		h2c_pkt[1] = si->mac_id & 0x7f;
> +		h2c_pkt[2] = (si->rate_id & 0x1f) |
> +			     (si->sgi_enable ? BIT(7) : 0);
> +		h2c_pkt[3] = ((si->bw_mode ? 3 : 1) & 0x3) |
> +			     (apply ? 0 : BIT(3));
> +		h2c_pkt[4] = si->ra_mask & 0xff;
> +		h2c_pkt[5] = (si->ra_mask >> 8) & 0xff;
> +		h2c_pkt[6] = (si->ra_mask >> 16) & 0xff;
> +		h2c_pkt[7] = (si->ra_mask >> 24) & 0xff;
> +
> +		si->ra_mask_last = si->ra_mask;
> +		si->init_ra_lv = 0;
> +
> +		rtw_fw_send_h2c_command(rtwdev, h2c_pkt);
> +		return;
> +	}
> +

I bet you don't need to modify rtw_fw_send_ra_info() at all.

>  	SET_RA_INFO_MACID(h2c_pkt, si->mac_id);
>  	SET_RA_INFO_RATE_ID(h2c_pkt, si->rate_id);
>  	SET_RA_INFO_INIT_RA_LVL(h2c_pkt, si->init_ra_lv);
> diff --git a/drivers/net/wireless/realtek/rtw88/main.h b/drivers/net/wireless/realtek/rtw88/main.h
> index 8f86f7c12de5..9c435c160b61 100644
> --- a/drivers/net/wireless/realtek/rtw88/main.h
> +++ b/drivers/net/wireless/realtek/rtw88/main.h
> @@ -782,6 +782,8 @@ struct rtw_sta_info {
>  	bool vht_enable;
>  	u8 init_ra_lv;
>  	u64 ra_mask;
> +	/* Last rate mask sent to the firmware, to gate no_update. */
> +	u64 ra_mask_last;
>  
>  	DECLARE_BITMAP(tid_ba, IEEE80211_NUM_TIDS);
>