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@xxxxxxxx>
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@xxxxxxxxx>
---
v9:
1: change the patch index from 1 to 2.
v8:
1: Fix usb_submit_urb() in f81232_resume() with GFP_NOIO, not
GFP_KERNEL.
v7:
1: Remove serial->suspending check
2: Add port priv is_port_open to save port open state. We'll
register interrupt-in urb in f81232_resume() when port is
opened.
3: Using usb_kill_urb for read/interrupt urb to ensure urb
stopped.
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 | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index d43ec999bc5e..f0de20a818cd 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -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 @@ 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 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;
}
--
2.7.4
