diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c index 530b77fc2f78..9262a2ac97f5 100644 --- a/drivers/usb/serial/f81232.c +++ b/drivers/usb/serial/f81232.c @@ -70,7 +70,6 @@ MODULE_DEVICE_TABLE(usb, combined_id_table); #define F81232_REGISTER_REQUEST 0xa0 #define F81232_GET_REGISTER 0xc0 #define F81232_SET_REGISTER 0x40 -#define F81534A_ACCESS_REG_RETRY 2 #define SERIAL_BASE_ADDRESS 0x0120 #define RECEIVE_BUFFER_REGISTER (0x00 + SERIAL_BASE_ADDRESS) @@ -824,36 +823,31 @@ static void f81232_lsr_worker(struct work_struct *work) static int f81534a_ctrl_set_register(struct usb_interface *intf, u16 reg, u16 size, void *val) { - struct usb_device *dev = interface_to_usbdev(intf); - int retry = F81534A_ACCESS_REG_RETRY; - int status; + return usb_control_msg_send(interface_to_usbdev(intf), + 0, + F81232_REGISTER_REQUEST, + F81232_SET_REGISTER, + reg, + 0, + val, + size, + USB_CTRL_SET_TIMEOUT, + GFP_KERNEL); +} - while (retry--) { - status = usb_control_msg_send(dev, - 0, - F81232_REGISTER_REQUEST, - F81232_SET_REGISTER, - reg, - 0, - val, - size, - USB_CTRL_SET_TIMEOUT, - GFP_KERNEL); - if (status) { - status = usb_translate_errors(status); - if (status == -EIO) - continue; - } - - break; - } - - if (status) { - dev_err(&intf->dev, "failed to set register 0x%x: %d\n", - reg, status); - } - - return status; +static int f81534a_ctrl_get_register(struct usb_interface *intf, u16 reg, + u16 size, void *val) +{ + return usb_control_msg_recv(interface_to_usbdev(intf), + 0, + F81232_REGISTER_REQUEST, + F81232_GET_REGISTER, + reg, + 0, + val, + size, + USB_CTRL_GET_TIMEOUT, + GFP_KERNEL); } static int f81534a_ctrl_enable_all_ports(struct usb_interface *intf, bool en) @@ -869,6 +863,29 @@ static int f81534a_ctrl_enable_all_ports(struct usb_interface *intf, bool en) * bit 0~11 : Serial port enable bit. */ if (en) { + /* + * The Fintek F81532A/534A/535/536 family relies on the + * F81534A_CTRL_CMD_ENABLE_PORT (116h) register during + * initialization to both determine serial port status and + * control port creation. + * + * If the driver experiences fast load/unload cycles, the + * device state may becomes unstable, resulting in the + * incomplete generation of serial ports. + * + * Performing a dummy read operation on the register prior + * to the initial write command resolves the issue. + * + * This clears the device's stale internal state. Subsequent + * write operations will correctly generate all serial ports. + */ + status = f81534a_ctrl_get_register(intf, + F81534A_CTRL_CMD_ENABLE_PORT, + sizeof(enable), + enable); + if (status) + return status; + enable[0] = 0xff; enable[1] = 0x8f; }