[PATCH v1] Bluetooth: btnxpuart: Enable flow control before checking boot signature

[Neeraj Sanjay Kale]

This enables flow control before checking for bootloader signature and
deciding whether FW download is needed or not. In case of V1 bootloader
chips w8987 and w8997, it is observed that if WLAN FW is downloaded first
and power save is enabled in wlan core, bootloader signatures are not
emitted by the BT core when the chip is put to sleep. This results in BT
FW download timeout error. By enabling the flow control, the host enables
its RTS pin, and an interrupt in chip's UART peripheral causes the
bootloader to wakeup, enabling the bootloader signatures, which then helps
in downloading the bluetooth FW file.

Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@xxxxxxx>
---
 drivers/bluetooth/btnxpuart.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
index 93f3afc0c0c8..3ee41a0d45e7 100644
--- a/drivers/bluetooth/btnxpuart.c
+++ b/drivers/bluetooth/btnxpuart.c
@@ -967,7 +967,7 @@ static int nxp_set_ind_reset(struct hci_dev *hdev, void *data)
 static int nxp_check_boot_sign(struct btnxpuart_dev *nxpdev)
 {
 	serdev_device_set_baudrate(nxpdev->serdev, HCI_NXP_PRI_BAUDRATE);
-	serdev_device_set_flow_control(nxpdev->serdev, 0);
+	serdev_device_set_flow_control(nxpdev->serdev, 1);
 	set_bit(BTNXPUART_CHECK_BOOT_SIGNATURE, &nxpdev->tx_state);
 
 	return wait_event_interruptible_timeout(nxpdev->check_boot_sign_wait_q,
-- 
2.34.1