Commit 1c6b7ab2 authored by Ji-Ze Hong (Peter Hong)'s avatar Ji-Ze Hong (Peter Hong) Committed by Johan Hovold
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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: default avatarJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
parent 804dbee1

drivers/usb/serial/f81232.c

+24 −1
Original line number Diff line number Diff line
@@ -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;

}

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