Add power reset for bluetooth via enable-gpios in h5_btrtl_open function. While testing the RTL8822CS SDIO WiFi/BT adapter, it was found that in some cases the kernel could not initialize BT firmware. However, manually resetting the adapter via gpio (off/on sequence) allows it to start correctly. Apparently, when the system starts, the adapter is in an undefined state (including unknown gpio state after starting uboot). A forced reset helps to initialize the adapter in most cases. It has been found experimentally that 100 ms is sufficient for a reset. Signed-off-by: Vyacheslav Bocharov <adeep@xxxxxxxxx> --- drivers/bluetooth/hci_h5.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c index 34286ffe0568..fdf504b0d265 100644 --- a/drivers/bluetooth/hci_h5.c +++ b/drivers/bluetooth/hci_h5.c @@ -966,6 +966,11 @@ static void h5_btrtl_open(struct h5 *h5) pm_runtime_enable(&h5->hu->serdev->dev); } + /* The controller needs reset to startup */ + gpiod_set_value_cansleep(h5->enable_gpio, 0); + gpiod_set_value_cansleep(h5->device_wake_gpio, 0); + msleep(100); + /* The controller needs up to 500ms to wakeup */ gpiod_set_value_cansleep(h5->enable_gpio, 1); gpiod_set_value_cansleep(h5->device_wake_gpio, 1); -- 2.30.2
