On Mon, Aug 5, 2019 at 9:15 PM Chris Chiu <chiu@xxxxxxxxxxxx> wrote: > > We have 3 laptops which connect the wifi by the same RTL8723BU. > The PCI VID/PID of the wifi chip is 10EC:B720 which is supported. > They have the same problem with the in-kernel rtl8xxxu driver, the > iperf (as a client to an ethernet-connected server) gets ~1Mbps. > Nevertheless, the signal strength is reported as around -40dBm, > which is quite good. From the wireshark capture, the tx rate for each > data and qos data packet is only 1Mbps. Compare to the Realtek driver > at https://github.com/lwfinger/rtl8723bu, the same iperf test gets > ~12Mbps or better. The signal strength is reported similarly around > -40dBm. That's why we want to improve. > > After reading the source code of the rtl8xxxu driver and Realtek's, the > major difference is that Realtek's driver has a watchdog which will keep > monitoring the signal quality and updating the rate mask just like the > rtl8xxxu_gen2_update_rate_mask() does if signal quality changes. > And this kind of watchdog also exists in rtlwifi driver of some specific > chips, ex rtl8192ee, rtl8188ee, rtl8723ae, rtl8821ae...etc. They have > the same member function named dm_watchdog and will invoke the > corresponding dm_refresh_rate_adaptive_mask to adjust the tx rate > mask. > > With this commit, the tx rate of each data and qos data packet will > be 39Mbps (MCS4) with the 0xF00000 as the tx rate mask. The 20th bit > to 23th bit means MCS4 to MCS7. It means that the firmware still picks > the lowest rate from the rate mask and explains why the tx rate of > data and qos data is always lowest 1Mbps because the default rate mask > passed is always 0xFFFFFFF ranges from the basic CCK rate, OFDM rate, > and MCS rate. However, with Realtek's driver, the tx rate observed from > wireshark under the same condition is almost 65Mbps or 72Mbps, which > indicating that rtl8xxxu could still be further improved. > > Signed-off-by: Chris Chiu <chiu@xxxxxxxxxxxx> > Reviewed-by: Daniel Drake <drake@xxxxxxxxxxxx> Tested-by: Kleintje Jens <jkleintje@xxxxxxxxxxxxxx> > --- > > > Notes: > v2: > - Fix errors and warnings complained by checkpatch.pl > - Replace data structure rate_adaptive by 2 member variables > - Make rtl8xxxu_wireless_mode non-static > - Runs refresh_rate_mask() only in station mode > v3: > - Remove ugly rtl8xxxu_watchdog data structure > - Make sure only one vif exists > v4: > - Move cancel_delayed_work from rtl8xxxu_disconnect to rtl8xxxu_stop > - Clear priv->vif in rtl8xxxu_remove_interface > - Add rateid as the function argument of update_rate_mask > - Rephrase the comment for priv->vif more explicit. > v5: > - Make refresh_rate_mask() generic for all sub-drivers. > - Add definitions for SNR related to help determine rssi_level > v6: > - Fix typo of the comment for priv->vif > v7: > - Fix reported bug of watchdog stop > - refer to the RxPWDBAll in vendor driver for SNR calculation > > > .../net/wireless/realtek/rtl8xxxu/rtl8xxxu.h | 55 ++++- > .../wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 229 +++++++++++++++++- > 2 files changed, 277 insertions(+), 7 deletions(-) > > diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h > index ade057d868f7..582c2a346cec 100644 > --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h > +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h > @@ -1187,6 +1187,48 @@ struct rtl8723bu_c2h { > > struct rtl8xxxu_fileops; > > +/*mlme related.*/ > +enum wireless_mode { > + WIRELESS_MODE_UNKNOWN = 0, > + /* Sub-Element */ > + WIRELESS_MODE_B = BIT(0), > + WIRELESS_MODE_G = BIT(1), > + WIRELESS_MODE_A = BIT(2), > + WIRELESS_MODE_N_24G = BIT(3), > + WIRELESS_MODE_N_5G = BIT(4), > + WIRELESS_AUTO = BIT(5), > + WIRELESS_MODE_AC = BIT(6), > + WIRELESS_MODE_MAX = 0x7F, > +}; > + > +/* from rtlwifi/wifi.h */ > +enum ratr_table_mode_new { > + RATEID_IDX_BGN_40M_2SS = 0, > + RATEID_IDX_BGN_40M_1SS = 1, > + RATEID_IDX_BGN_20M_2SS_BN = 2, > + RATEID_IDX_BGN_20M_1SS_BN = 3, > + RATEID_IDX_GN_N2SS = 4, > + RATEID_IDX_GN_N1SS = 5, > + RATEID_IDX_BG = 6, > + RATEID_IDX_G = 7, > + RATEID_IDX_B = 8, > + RATEID_IDX_VHT_2SS = 9, > + RATEID_IDX_VHT_1SS = 10, > + RATEID_IDX_MIX1 = 11, > + RATEID_IDX_MIX2 = 12, > + RATEID_IDX_VHT_3SS = 13, > + RATEID_IDX_BGN_3SS = 14, > +}; > + > +#define RTL8XXXU_RATR_STA_INIT 0 > +#define RTL8XXXU_RATR_STA_HIGH 1 > +#define RTL8XXXU_RATR_STA_MID 2 > +#define RTL8XXXU_RATR_STA_LOW 3 > + > +#define RTL8XXXU_NOISE_FLOOR_MIN -100 > +#define RTL8XXXU_SNR_THRESH_HIGH 50 > +#define RTL8XXXU_SNR_THRESH_LOW 20 > + > struct rtl8xxxu_priv { > struct ieee80211_hw *hw; > struct usb_device *udev; > @@ -1291,6 +1333,13 @@ struct rtl8xxxu_priv { > u8 pi_enabled:1; > u8 no_pape:1; > u8 int_buf[USB_INTR_CONTENT_LENGTH]; > + u8 rssi_level; > + /* > + * Only one virtual interface permitted because only STA mode > + * is supported and no iface_combinations are provided. > + */ > + struct ieee80211_vif *vif; > + struct delayed_work ra_watchdog; > }; > > struct rtl8xxxu_rx_urb { > @@ -1326,7 +1375,7 @@ struct rtl8xxxu_fileops { > void (*set_tx_power) (struct rtl8xxxu_priv *priv, int channel, > bool ht40); > void (*update_rate_mask) (struct rtl8xxxu_priv *priv, > - u32 ramask, int sgi); > + u32 ramask, u8 rateid, int sgi); > void (*report_connect) (struct rtl8xxxu_priv *priv, > u8 macid, bool connect); > void (*fill_txdesc) (struct ieee80211_hw *hw, struct ieee80211_hdr *hdr, > @@ -1411,9 +1460,9 @@ void rtl8xxxu_gen2_config_channel(struct ieee80211_hw *hw); > void rtl8xxxu_gen1_usb_quirks(struct rtl8xxxu_priv *priv); > void rtl8xxxu_gen2_usb_quirks(struct rtl8xxxu_priv *priv); > void rtl8xxxu_update_rate_mask(struct rtl8xxxu_priv *priv, > - u32 ramask, int sgi); > + u32 ramask, u8 rateid, int sgi); > void rtl8xxxu_gen2_update_rate_mask(struct rtl8xxxu_priv *priv, > - u32 ramask, int sgi); > + u32 ramask, u8 rateid, int sgi); > void rtl8xxxu_gen1_report_connect(struct rtl8xxxu_priv *priv, > u8 macid, bool connect); > void rtl8xxxu_gen2_report_connect(struct rtl8xxxu_priv *priv, > diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c > index c6c41fb962ff..a6f358b9e447 100644 > --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c > +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c > @@ -4304,7 +4304,8 @@ static void rtl8xxxu_sw_scan_complete(struct ieee80211_hw *hw, > rtl8xxxu_write8(priv, REG_BEACON_CTRL, val8); > } > > -void rtl8xxxu_update_rate_mask(struct rtl8xxxu_priv *priv, u32 ramask, int sgi) > +void rtl8xxxu_update_rate_mask(struct rtl8xxxu_priv *priv, > + u32 ramask, u8 rateid, int sgi) > { > struct h2c_cmd h2c; > > @@ -4324,7 +4325,7 @@ void rtl8xxxu_update_rate_mask(struct rtl8xxxu_priv *priv, u32 ramask, int sgi) > } > > void rtl8xxxu_gen2_update_rate_mask(struct rtl8xxxu_priv *priv, > - u32 ramask, int sgi) > + u32 ramask, u8 rateid, int sgi) > { > struct h2c_cmd h2c; > u8 bw = 0; > @@ -4338,7 +4339,7 @@ void rtl8xxxu_gen2_update_rate_mask(struct rtl8xxxu_priv *priv, > h2c.b_macid_cfg.ramask3 = (ramask >> 24) & 0xff; > > h2c.ramask.arg = 0x80; > - h2c.b_macid_cfg.data1 = 0; > + h2c.b_macid_cfg.data1 = rateid; > if (sgi) > h2c.b_macid_cfg.data1 |= BIT(7); > > @@ -4478,6 +4479,40 @@ static void rtl8xxxu_set_basic_rates(struct rtl8xxxu_priv *priv, u32 rate_cfg) > rtl8xxxu_write8(priv, REG_INIRTS_RATE_SEL, rate_idx); > } > > +static u16 > +rtl8xxxu_wireless_mode(struct ieee80211_hw *hw, struct ieee80211_sta *sta) > +{ > + u16 network_type = WIRELESS_MODE_UNKNOWN; > + u32 rate_mask; > + > + rate_mask = (sta->supp_rates[0] & 0xfff) | > + (sta->ht_cap.mcs.rx_mask[0] << 12) | > + (sta->ht_cap.mcs.rx_mask[0] << 20); > + > + if (hw->conf.chandef.chan->band == NL80211_BAND_5GHZ) { > + if (sta->vht_cap.vht_supported) > + network_type = WIRELESS_MODE_AC; > + else if (sta->ht_cap.ht_supported) > + network_type = WIRELESS_MODE_N_5G; > + > + network_type |= WIRELESS_MODE_A; > + } else { > + if (sta->vht_cap.vht_supported) > + network_type = WIRELESS_MODE_AC; > + else if (sta->ht_cap.ht_supported) > + network_type = WIRELESS_MODE_N_24G; > + > + if (sta->supp_rates[0] <= 0xf) > + network_type |= WIRELESS_MODE_B; > + else if (sta->supp_rates[0] & 0xf) > + network_type |= (WIRELESS_MODE_B | WIRELESS_MODE_G); > + else > + network_type |= WIRELESS_MODE_G; > + } > + > + return network_type; > +} > + > static void > rtl8xxxu_bss_info_changed(struct ieee80211_hw *hw, struct ieee80211_vif *vif, > struct ieee80211_bss_conf *bss_conf, u32 changed) > @@ -4520,7 +4555,10 @@ rtl8xxxu_bss_info_changed(struct ieee80211_hw *hw, struct ieee80211_vif *vif, > sgi = 1; > rcu_read_unlock(); > > - priv->fops->update_rate_mask(priv, ramask, sgi); > + priv->vif = vif; > + priv->rssi_level = RTL8XXXU_RATR_STA_INIT; > + > + priv->fops->update_rate_mask(priv, ramask, 0, sgi); > > rtl8xxxu_write8(priv, REG_BCN_MAX_ERR, 0xff); > > @@ -5464,6 +5502,10 @@ static int rtl8xxxu_add_interface(struct ieee80211_hw *hw, > > switch (vif->type) { > case NL80211_IFTYPE_STATION: > + if (!priv->vif) > + priv->vif = vif; > + else > + return -EOPNOTSUPP; > rtl8xxxu_stop_tx_beacon(priv); > > val8 = rtl8xxxu_read8(priv, REG_BEACON_CTRL); > @@ -5487,6 +5529,9 @@ static void rtl8xxxu_remove_interface(struct ieee80211_hw *hw, > struct rtl8xxxu_priv *priv = hw->priv; > > dev_dbg(&priv->udev->dev, "%s\n", __func__); > + > + if (priv->vif) > + priv->vif = NULL; > } > > static int rtl8xxxu_config(struct ieee80211_hw *hw, u32 changed) > @@ -5772,6 +5817,177 @@ rtl8xxxu_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif, > return 0; > } > > +static u8 rtl8xxxu_signal_to_snr(int signal) > +{ > + if (signal < RTL8XXXU_NOISE_FLOOR_MIN) > + signal = RTL8XXXU_NOISE_FLOOR_MIN; > + else if (signal > 0) > + signal = 0; > + return (u8)(signal - RTL8XXXU_NOISE_FLOOR_MIN); > +} > + > +static void rtl8xxxu_refresh_rate_mask(struct rtl8xxxu_priv *priv, > + int signal, struct ieee80211_sta *sta) > +{ > + struct ieee80211_hw *hw = priv->hw; > + u16 wireless_mode; > + u8 rssi_level, ratr_idx; > + u8 txbw_40mhz; > + u8 snr, snr_thresh_high, snr_thresh_low; > + u8 go_up_gap = 5; > + > + rssi_level = priv->rssi_level; > + snr = rtl8xxxu_signal_to_snr(signal); > + snr_thresh_high = RTL8XXXU_SNR_THRESH_HIGH; > + snr_thresh_low = RTL8XXXU_SNR_THRESH_LOW; > + txbw_40mhz = (hw->conf.chandef.width == NL80211_CHAN_WIDTH_40) ? 1 : 0; > + > + switch (rssi_level) { > + case RTL8XXXU_RATR_STA_MID: > + snr_thresh_high += go_up_gap; > + break; > + case RTL8XXXU_RATR_STA_LOW: > + snr_thresh_high += go_up_gap; > + snr_thresh_low += go_up_gap; > + break; > + default: > + break; > + } > + > + if (snr > snr_thresh_high) > + rssi_level = RTL8XXXU_RATR_STA_HIGH; > + else if (snr > snr_thresh_low) > + rssi_level = RTL8XXXU_RATR_STA_MID; > + else > + rssi_level = RTL8XXXU_RATR_STA_LOW; > + > + if (rssi_level != priv->rssi_level) { > + int sgi = 0; > + u32 rate_bitmap = 0; > + > + rcu_read_lock(); > + rate_bitmap = (sta->supp_rates[0] & 0xfff) | > + (sta->ht_cap.mcs.rx_mask[0] << 12) | > + (sta->ht_cap.mcs.rx_mask[1] << 20); > + if (sta->ht_cap.cap & > + (IEEE80211_HT_CAP_SGI_40 | IEEE80211_HT_CAP_SGI_20)) > + sgi = 1; > + rcu_read_unlock(); > + > + wireless_mode = rtl8xxxu_wireless_mode(hw, sta); > + switch (wireless_mode) { > + case WIRELESS_MODE_B: > + ratr_idx = RATEID_IDX_B; > + if (rate_bitmap & 0x0000000c) > + rate_bitmap &= 0x0000000d; > + else > + rate_bitmap &= 0x0000000f; > + break; > + case WIRELESS_MODE_A: > + case WIRELESS_MODE_G: > + ratr_idx = RATEID_IDX_G; > + if (rssi_level == RTL8XXXU_RATR_STA_HIGH) > + rate_bitmap &= 0x00000f00; > + else > + rate_bitmap &= 0x00000ff0; > + break; > + case (WIRELESS_MODE_B | WIRELESS_MODE_G): > + ratr_idx = RATEID_IDX_BG; > + if (rssi_level == RTL8XXXU_RATR_STA_HIGH) > + rate_bitmap &= 0x00000f00; > + else if (rssi_level == RTL8XXXU_RATR_STA_MID) > + rate_bitmap &= 0x00000ff0; > + else > + rate_bitmap &= 0x00000ff5; > + break; > + case WIRELESS_MODE_N_24G: > + case WIRELESS_MODE_N_5G: > + case (WIRELESS_MODE_G | WIRELESS_MODE_N_24G): > + case (WIRELESS_MODE_A | WIRELESS_MODE_N_5G): > + if (priv->tx_paths == 2 && priv->rx_paths == 2) > + ratr_idx = RATEID_IDX_GN_N2SS; > + else > + ratr_idx = RATEID_IDX_GN_N1SS; > + case (WIRELESS_MODE_B | WIRELESS_MODE_G | WIRELESS_MODE_N_24G): > + case (WIRELESS_MODE_B | WIRELESS_MODE_N_24G): > + if (txbw_40mhz) { > + if (priv->tx_paths == 2 && priv->rx_paths == 2) > + ratr_idx = RATEID_IDX_BGN_40M_2SS; > + else > + ratr_idx = RATEID_IDX_BGN_40M_1SS; > + } else { > + if (priv->tx_paths == 2 && priv->rx_paths == 2) > + ratr_idx = RATEID_IDX_BGN_20M_2SS_BN; > + else > + ratr_idx = RATEID_IDX_BGN_20M_1SS_BN; > + } > + > + if (priv->tx_paths == 2 && priv->rx_paths == 2) { > + if (rssi_level == RTL8XXXU_RATR_STA_HIGH) { > + rate_bitmap &= 0x0f8f0000; > + } else if (rssi_level == RTL8XXXU_RATR_STA_MID) { > + rate_bitmap &= 0x0f8ff000; > + } else { > + if (txbw_40mhz) > + rate_bitmap &= 0x0f8ff015; > + else > + rate_bitmap &= 0x0f8ff005; > + } > + } else { > + if (rssi_level == RTL8XXXU_RATR_STA_HIGH) { > + rate_bitmap &= 0x000f0000; > + } else if (rssi_level == RTL8XXXU_RATR_STA_MID) { > + rate_bitmap &= 0x000ff000; > + } else { > + if (txbw_40mhz) > + rate_bitmap &= 0x000ff015; > + else > + rate_bitmap &= 0x000ff005; > + } > + } > + break; > + default: > + ratr_idx = RATEID_IDX_BGN_40M_2SS; > + rate_bitmap &= 0x0fffffff; > + break; > + } > + > + priv->rssi_level = rssi_level; > + priv->fops->update_rate_mask(priv, rate_bitmap, ratr_idx, sgi); > + } > +} > + > +static void rtl8xxxu_watchdog_callback(struct work_struct *work) > +{ > + struct ieee80211_vif *vif; > + struct rtl8xxxu_priv *priv; > + > + priv = container_of(work, struct rtl8xxxu_priv, ra_watchdog.work); > + vif = priv->vif; > + > + if (vif && vif->type == NL80211_IFTYPE_STATION) { > + int signal; > + struct ieee80211_sta *sta; > + > + rcu_read_lock(); > + sta = ieee80211_find_sta(vif, vif->bss_conf.bssid); > + if (!sta) { > + struct device *dev = &priv->udev->dev; > + > + dev_info(dev, "%s: no sta found\n", __func__); > + rcu_read_unlock(); > + goto out; > + } > + rcu_read_unlock(); > + > + signal = ieee80211_ave_rssi(vif); > + rtl8xxxu_refresh_rate_mask(priv, signal, sta); > + } > + > +out: > + schedule_delayed_work(&priv->ra_watchdog, 2 * HZ); > +} > + > static int rtl8xxxu_start(struct ieee80211_hw *hw) > { > struct rtl8xxxu_priv *priv = hw->priv; > @@ -5828,6 +6044,8 @@ static int rtl8xxxu_start(struct ieee80211_hw *hw) > > ret = rtl8xxxu_submit_rx_urb(priv, rx_urb); > } > + > + schedule_delayed_work(&priv->ra_watchdog, 2 * HZ); > exit: > /* > * Accept all data and mgmt frames > @@ -5879,6 +6097,8 @@ static void rtl8xxxu_stop(struct ieee80211_hw *hw) > if (priv->usb_interrupts) > rtl8xxxu_write32(priv, REG_USB_HIMR, 0); > > + cancel_delayed_work_sync(&priv->ra_watchdog); > + > rtl8xxxu_free_rx_resources(priv); > rtl8xxxu_free_tx_resources(priv); > } > @@ -6051,6 +6271,7 @@ static int rtl8xxxu_probe(struct usb_interface *interface, > INIT_LIST_HEAD(&priv->rx_urb_pending_list); > spin_lock_init(&priv->rx_urb_lock); > INIT_WORK(&priv->rx_urb_wq, rtl8xxxu_rx_urb_work); > + INIT_DELAYED_WORK(&priv->ra_watchdog, rtl8xxxu_watchdog_callback); > > usb_set_intfdata(interface, hw); > > -- > 2.20.1 >
