USB: serial: f81232: clear overrun flag

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 <oneukum@suse.com>
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Ji-Ze Hong (Peter Hong) 2019-04-30 09:22:30 +08:00 committed by Johan Hovold
parent 804dbee1e4
commit 1c6b7ab2dd

View file

@ -41,12 +41,14 @@ 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;
struct work_struct lsr_work;
struct work_struct interrupt_work;
struct usb_serial_port *port;
};
@ -282,6 +284,7 @@ exit:
static void f81232_process_read_urb(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
struct f81232_private *priv = usb_get_serial_port_data(port);
unsigned char *data = urb->transfer_buffer;
char tty_flag;
unsigned int i;
@ -315,6 +318,7 @@ static void f81232_process_read_urb(struct urb *urb)
if (lsr & UART_LSR_OE) {
port->icount.overrun++;
schedule_work(&priv->lsr_work);
tty_insert_flip_char(&port->port, 0,
TTY_OVERRUN);
}
@ -562,6 +566,7 @@ static void f81232_close(struct usb_serial_port *port)
usb_serial_generic_close(port);
usb_kill_urb(port->interrupt_in_urb);
flush_work(&port_priv->interrupt_work);
flush_work(&port_priv->lsr_work);
}
static void f81232_dtr_rts(struct usb_serial_port *port, int on)
@ -606,6 +611,21 @@ 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;
@ -616,6 +636,7 @@ 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);
@ -646,8 +667,10 @@ static int f81232_suspend(struct usb_serial *serial, pm_message_t message)
usb_kill_urb(port->interrupt_in_urb);
if (port_priv)
if (port_priv) {
flush_work(&port_priv->interrupt_work);
flush_work(&port_priv->lsr_work);
}
return 0;
}