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. Chris > We may need to put in place so > > Cheers, > Jesme code to detect whether we have normal > or inverse configuration of the dongle otherwise? > > I really appreciate you're digging into this!
