On 7/4/19 10:27 PM, Chris Chiu wrote: > On Fri, Jul 5, 2019 at 12:43 AM Jes Sorensen <jes.sorensen@xxxxxxxxx> wrote: >> >> On 7/4/19 6:55 AM, Chris Chiu wrote: >>> The WiFi tx power of RTL8723BU is extremely low after booting. So >>> the WiFi scan gives very limited AP list and it always fails to >>> connect to the selected AP. This module only supports 1x1 antenna >>> and the antenna is switched to bluetooth due to some incorrect >>> register settings. >>> >>> Compare with the vendor driver https://github.com/lwfinger/rtl8723bu, >>> we realized that the 8723bu's enable_rf() does the same thing as >>> rtw_btcoex_HAL_Initialize() in vendor driver. And it by default >>> sets the antenna path to BTC_ANT_PATH_BT which we verified it's >>> the cause of the wifi weak tx power. The vendor driver will set >>> the antenna path to BTC_ANT_PATH_PTA in the consequent btcoexist >>> mechanism, by the function halbtc8723b1ant_PsTdma. >>> >>> This commit hand over the antenna control to PTA(Packet Traffic >>> Arbitration), which compares the weight of bluetooth/wifi traffic >>> then determine whether to continue current wifi traffic or not. >>> After PTA take control, The wifi signal will be back to normal and >>> the bluetooth scan can also work at the same time. However, the >>> btcoexist still needs to be handled under different circumstances. >>> If there's a BT connection established, the wifi still fails to >>> connect until BT disconnected. >>> >>> Signed-off-by: Chris Chiu <chiu@xxxxxxxxxxxx> >>> --- >>> >>> >>> Note: >>> v2: >>> - Replace BIT(11) with the descriptive definition >>> - Meaningful comment for the REG_S0S1_PATH_SWITCH setting >>> >>> >>> drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c | 11 ++++++++--- >>> drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 3 ++- >>> 2 files changed, 10 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c >>> index 3adb1d3d47ac..ceffe05bd65b 100644 >>> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c >>> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c >>> @@ -1525,7 +1525,7 @@ static void rtl8723b_enable_rf(struct rtl8xxxu_priv *priv) >>> /* >>> * WLAN action by PTA >>> */ >>> - rtl8xxxu_write8(priv, REG_WLAN_ACT_CONTROL_8723B, 0x04); >>> + rtl8xxxu_write8(priv, REG_WLAN_ACT_CONTROL_8723B, 0x0c); >>> >>> /* >>> * BT select S0/S1 controlled by WiFi >>> @@ -1568,9 +1568,14 @@ static void rtl8723b_enable_rf(struct rtl8xxxu_priv *priv) >>> rtl8xxxu_gen2_h2c_cmd(priv, &h2c, sizeof(h2c.ant_sel_rsv)); >>> >>> /* >>> - * 0x280, 0x00, 0x200, 0x80 - not clear >>> + * Different settings per different antenna position. >>> + * Antenna Position: | Normal Inverse >>> + * -------------------------------------------------- >>> + * Antenna switch to BT: | 0x280, 0x00 >>> + * Antenna switch to WiFi: | 0x0, 0x280 >>> + * Antenna switch to PTA: | 0x200, 0x80 >>> */ >>> - rtl8xxxu_write32(priv, REG_S0S1_PATH_SWITCH, 0x00); >>> + rtl8xxxu_write32(priv, REG_S0S1_PATH_SWITCH, 0x80); >> >> Per the documentation, shouldn't this be set to 0x200 then rather than 0x80? >> > Per the code before REG_S0S1_PATH_SWITCH setting, the driver has told > the co-processor the antenna is inverse. > memset(&h2c, 0, sizeof(struct h2c_cmd)); > h2c.ant_sel_rsv.cmd = H2C_8723B_ANT_SEL_RSV; > h2c.ant_sel_rsv.ant_inverse = 1; > h2c.ant_sel_rsv.int_switch_type = 0; > rtl8xxxu_gen2_h2c_cmd(priv, &h2c, sizeof(h2c.ant_sel_rsv)); > > At least the current modification is consistent with the antenna > inverse setting. > I'll verify on vendor driver about when/how the inverse be determined. Fair enough :) Cheers, Jes
