The F81232 will report data and LSR with bulk like following format: bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]...
LSR will auto clear frame/parity/break error flag when reading by H/W, but overrrun will only cleared when reading LSR. So this patch add a worker to read LSR when overrun and flush the worker on close() & suspend(). Cc: Oliver Neukum <[email protected]> Signed-off-by: Ji-Ze Hong (Peter Hong) <[email protected]> --- V6: 1: Add deferred_lsr_work_needed to re-trigger when f81232_resume() v5: 1: Source code base revert to v3 and remove all v4 changes. 2: Add serial->suspending check in f81232_process_read_urb() before schedule_work(&priv->lsr_work) to avoid race condition. v4: 1: Add serial->suspending check in f81232_lsr_worker() to avoid re-trigger 2: Add port_priv-lsr_work_resched to re-trigger LSR worker v3: 1: Add flush_work(&port_priv->lsr_work) in f81232_suspend(). v2: 1: Add flush_work(&port_priv->lsr_work) in f81232_close(). drivers/usb/serial/f81232.c | 55 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c index 0dcdcb4b2cde..600e1f4d94e0 100644 --- a/drivers/usb/serial/f81232.c +++ b/drivers/usb/serial/f81232.c @@ -41,12 +41,15 @@ MODULE_DEVICE_TABLE(usb, id_table); #define FIFO_CONTROL_REGISTER (0x02 + SERIAL_BASE_ADDRESS) #define LINE_CONTROL_REGISTER (0x03 + SERIAL_BASE_ADDRESS) #define MODEM_CONTROL_REGISTER (0x04 + SERIAL_BASE_ADDRESS) +#define LINE_STATUS_REGISTER (0x05 + SERIAL_BASE_ADDRESS) #define MODEM_STATUS_REGISTER (0x06 + SERIAL_BASE_ADDRESS) struct f81232_private { struct mutex lock; u8 modem_control; u8 modem_status; + bool deferred_lsr_work_needed; + struct work_struct lsr_work; struct work_struct interrupt_work; struct usb_serial_port *port; }; @@ -282,6 +285,8 @@ static void f81232_read_int_callback(struct urb *urb) static void f81232_process_read_urb(struct urb *urb) { struct usb_serial_port *port = urb->context; + struct usb_serial *serial = port->serial; + struct f81232_private *priv = usb_get_serial_port_data(port); unsigned char *data = urb->transfer_buffer; char tty_flag; unsigned int i; @@ -315,6 +320,12 @@ static void f81232_process_read_urb(struct urb *urb) if (lsr & UART_LSR_OE) { port->icount.overrun++; + + if (!serial->suspending) + schedule_work(&priv->lsr_work); + else + priv->deferred_lsr_work_needed = true; + tty_insert_flip_char(&port->port, 0, TTY_OVERRUN); } @@ -556,9 +567,12 @@ static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port) static void f81232_close(struct usb_serial_port *port) { + struct f81232_private *port_priv = usb_get_serial_port_data(port); + f81232_port_disable(port); usb_serial_generic_close(port); usb_kill_urb(port->interrupt_in_urb); + flush_work(&port_priv->lsr_work); } static void f81232_dtr_rts(struct usb_serial_port *port, int on) @@ -603,6 +617,21 @@ static void f81232_interrupt_work(struct work_struct *work) f81232_read_msr(priv->port); } +static void f81232_lsr_worker(struct work_struct *work) +{ + struct f81232_private *priv; + struct usb_serial_port *port; + int status; + u8 tmp; + + priv = container_of(work, struct f81232_private, lsr_work); + port = priv->port; + + status = f81232_get_register(port, LINE_STATUS_REGISTER, &tmp); + if (status) + dev_warn(&port->dev, "read LSR failed: %d\n", status); +} + static int f81232_port_probe(struct usb_serial_port *port) { struct f81232_private *priv; @@ -613,6 +642,7 @@ static int f81232_port_probe(struct usb_serial_port *port) mutex_init(&priv->lock); INIT_WORK(&priv->interrupt_work, f81232_interrupt_work); + INIT_WORK(&priv->lsr_work, f81232_lsr_worker); usb_set_serial_port_data(port, priv); @@ -632,6 +662,29 @@ static int f81232_port_remove(struct usb_serial_port *port) return 0; } +static int f81232_suspend(struct usb_serial *serial, pm_message_t message) +{ + struct f81232_private *port_priv; + + port_priv = usb_get_serial_port_data(serial->port[0]); + flush_work(&port_priv->lsr_work); + + return 0; +} + +static int f81232_resume(struct usb_serial *serial) +{ + struct f81232_private *port_priv; + + port_priv = usb_get_serial_port_data(serial->port[0]); + if (port_priv->deferred_lsr_work_needed) { + port_priv->deferred_lsr_work_needed = false; + schedule_work(&port_priv->lsr_work); + } + + return usb_serial_generic_resume(serial); +} + static struct usb_serial_driver f81232_device = { .driver = { .owner = THIS_MODULE, @@ -655,6 +708,8 @@ static struct usb_serial_driver f81232_device = { .read_int_callback = f81232_read_int_callback, .port_probe = f81232_port_probe, .port_remove = f81232_port_remove, + .suspend = f81232_suspend, + .resume = f81232_resume, }; static struct usb_serial_driver * const serial_drivers[] = { -- 2.7.4
