From: Bitterblue Smith The Realtek wifi 6/7 devices which support USB 3 are weird: when first plugged in, they pretend to be USB 2. The driver needs to send some commands to the device, which make it disappear and come back as a USB 3 device. Implement the required commands in rtw89. When a USB 3 device is plugged into a USB 2 port, rtw89 will try to switch it to USB 3 mode only once. The device will disappear and come back still in USB 2 mode, of course. Some people experience heavy interference in the 2.4 GHz band in USB 3 mode, so add a module parameter switch_usb_mode with the default value 1 to let people disable the switching. Tested with RTL8832BU and RTL8832CU. Signed-off-by: Bitterblue Smith Signed-off-by: Devin Wittmayer Tested-by: Devin Wittmayer --- drivers/net/wireless/realtek/rtw89/reg.h | 4 +++ drivers/net/wireless/realtek/rtw89/usb.c | 41 ++++++++++++++++++++++++ 2 files changed, 45 insertions(+) diff --git a/drivers/net/wireless/realtek/rtw89/reg.h b/drivers/net/wireless/realtek/rtw89/reg.h index 42ffe83931a3..7d4c085d9fb2 100644 --- a/drivers/net/wireless/realtek/rtw89/reg.h +++ b/drivers/net/wireless/realtek/rtw89/reg.h @@ -164,6 +164,10 @@ #define R_AX_DBG_PORT_SEL 0x00C0 #define B_AX_DEBUG_ST_MASK GENMASK(31, 0) +#define R_AX_PAD_CTRL2 0x00C4 +#define U2SWITCHU3 0xB +#define USB_SWITCH_DELAY 0xF + #define R_AX_PMC_DBG_CTRL2 0x00CC #define B_AX_SYSON_DIS_PMCR_AX_WRMSK BIT(2) diff --git a/drivers/net/wireless/realtek/rtw89/usb.c b/drivers/net/wireless/realtek/rtw89/usb.c index 767a95f759b1..4fb25791d118 100644 --- a/drivers/net/wireless/realtek/rtw89/usb.c +++ b/drivers/net/wireless/realtek/rtw89/usb.c @@ -9,6 +9,11 @@ #include "txrx.h" #include "usb.h" +static bool rtw89_switch_usb_mode = true; +module_param_named(switch_usb_mode, rtw89_switch_usb_mode, bool, 0644); +MODULE_PARM_DESC(switch_usb_mode, + "Set to N to disable switching to USB 3 mode to avoid potential interference in the 2.4 GHz band (default: Y)"); + static void rtw89_usb_read_port_complete(struct urb *urb); static void rtw89_usb_vendorreq(struct rtw89_dev *rtwdev, u32 addr, @@ -1027,6 +1032,35 @@ static void rtw89_usb_intf_deinit(struct rtw89_dev *rtwdev, usb_set_intfdata(intf, NULL); } +static int rtw89_usb_switch_mode(struct rtw89_dev *rtwdev) +{ + struct rtw89_usb *rtwusb = rtw89_usb_priv(rtwdev); + + if (!rtw89_switch_usb_mode) + return 0; + + /* No known USB 3 devices with this chip. */ + if (rtwdev->chip->chip_id == RTL8851B) + return 0; + + if (rtwusb->udev->speed == USB_SPEED_SUPER) + return 0; + + rtw89_debug(rtwdev, RTW89_DBG_HCI, "%s: pad_ctrl2: %#x %#x\n", + __func__, + rtw89_read8(rtwdev, R_AX_PAD_CTRL2 + 1), + rtw89_read8(rtwdev, R_AX_PAD_CTRL2 + 2)); + + /* Already tried to switch but it's a USB 2 port. */ + if (rtw89_read8(rtwdev, R_AX_PAD_CTRL2 + 1) == USB_SWITCH_DELAY) + return 0; + + rtw89_write8(rtwdev, R_AX_PAD_CTRL2 + 1, USB_SWITCH_DELAY); + rtw89_write8(rtwdev, R_AX_PAD_CTRL2 + 2, U2SWITCHU3); + + return 1; +} + int rtw89_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) { @@ -1059,6 +1093,13 @@ int rtw89_usb_probe(struct usb_interface *intf, goto err_free_hw; } + ret = rtw89_usb_switch_mode(rtwdev); + if (ret) { + /* Not a fail, but we do need to skip rtw89_core_register. */ + ret = 0; + goto err_intf_deinit; + } + if (rtwusb->udev->speed == USB_SPEED_SUPER) rtwdev->hci.dle_type = RTW89_HCI_DLE_TYPE_USB3; else -- 2.53.0