1 files changed, 75 insertions, 15 deletions

diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index 12a265c4a13b..e1173c1aee37 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -131,6 +131,7 @@ struct cypress_private {
         int write_urb_in_use;              /* write urb in use indicator */
         int write_urb_interval;            /* interval to use for write urb */
         int read_urb_interval;             /* interval to use for read urb */
+        int comm_is_ok;                    /* true if communication is (still) ok */
         int termios_initialized;
         __u8 line_control;                 /* holds dtr / rts value */
         __u8 current_status;               /* received from last read - info on dsr,cts,cd,ri,etc */
@@ -170,6 +171,7 @@ static int  cypress_tiocmset		(struct usb_serial_port *port, struct file *file,
 static int  cypress_chars_in_buffer     (struct usb_serial_port *port);
 static void cypress_throttle            (struct usb_serial_port *port);
 static void cypress_unthrottle          (struct usb_serial_port *port);
+static void cypress_set_dead            (struct usb_serial_port *port);
 static void cypress_read_int_callback   (struct urb *urb, struct pt_regs *regs);
 static void cypress_write_int_callback  (struct urb *urb, struct pt_regs *regs);
 /* baud helper functions */
@@ -290,6 +292,9 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
         
         priv = usb_get_serial_port_data(port);
 
+        if (!priv->comm_is_ok)
+                return -ENODEV;
+
         switch(cypress_request_type) {
                 case CYPRESS_SET_CONFIG:
 
@@ -369,9 +374,10 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
 
                         } while (retval != 8 && retval != -ENODEV);
 
-                        if (retval != 8)
+                        if (retval != 8) {
                                 err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
-                        else {
+                                cypress_set_dead(port);
+                        } else {
                                 spin_lock_irqsave(&priv->lock, flags);
                                 priv->baud_rate = new_baudrate;
                                 priv->cbr_mask = baud_mask;
@@ -396,6 +402,7 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
 
                         if (retval != 5) {
                                 err("%s - failed to retrieve serial line settings - %d", __FUNCTION__, retval);
+                                cypress_set_dead(port);
                                 return retval;
                         } else {
                                 spin_lock_irqsave(&priv->lock, flags);
@@ -417,6 +424,24 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
 } /* cypress_serial_control */
 
 
+static void cypress_set_dead(struct usb_serial_port *port)
+{
+        struct cypress_private *priv = usb_get_serial_port_data(port);
+        unsigned long flags;
+
+        spin_lock_irqsave(&priv->lock, flags);
+        if (!priv->comm_is_ok) {
+                spin_unlock_irqrestore(&priv->lock, flags);
+                return;
+        }
+        priv->comm_is_ok = 0;
+        spin_unlock_irqrestore(&priv->lock, flags);
+
+        err("cypress_m8 suspending failing port %d - interval might be too short",
+            port->number);
+}
+
+
 /* given a baud mask, it will return integer baud on success */
 static int mask_to_rate (unsigned mask)
 {
@@ -478,6 +503,7 @@ static int generic_startup (struct usb_serial *serial)
         if (!priv)
                 return -ENOMEM;
 
+        priv->comm_is_ok = !0;
         spin_lock_init(&priv->lock);
         priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
         if (priv->buf == NULL) {
@@ -595,6 +621,9 @@ static int cypress_open (struct usb_serial_port *port, struct file *filp)
 
         dbg("%s - port %d", __FUNCTION__, port->number);
 
+        if (!priv->comm_is_ok)
+                return -EIO;
+
         /* clear halts before open */
         usb_clear_halt(serial->dev, 0x81);
         usb_clear_halt(serial->dev, 0x02);
@@ -639,6 +668,7 @@ static int cypress_open (struct usb_serial_port *port, struct file *filp)
 
         if (result){
                 dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
+                cypress_set_dead(port);
         }
 
         return result;
@@ -743,6 +773,9 @@ static void cypress_send(struct usb_serial_port *port)
         struct cypress_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
         
+        if (!priv->comm_is_ok)
+                return;
+
         dbg("%s - port %d", __FUNCTION__, port->number);
         dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
         
@@ -825,6 +858,7 @@ send:
                 dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__,
                         result);
                 priv->write_urb_in_use = 0;
+                cypress_set_dead(port);
         }
 
         spin_lock_irqsave(&priv->lock, flags);
@@ -1225,13 +1259,18 @@ static void cypress_unthrottle (struct usb_serial_port *port)
         priv->rx_flags = 0;
         spin_unlock_irqrestore(&priv->lock, flags);
 
+        if (!priv->comm_is_ok)
+                return;
+
         if (actually_throttled) {
                 port->interrupt_in_urb->dev = port->serial->dev;
 
                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
-                if (result)
+                if (result) {
                         dev_err(&port->dev, "%s - failed submitting read urb, "
                                         "error %d\n", __FUNCTION__, result);
+                        cypress_set_dead(port);
+                }
         }
 }
 
@@ -1251,9 +1290,22 @@ static void cypress_read_int_callback(struct urb *urb, struct pt_regs *regs)
 
         dbg("%s - port %d", __FUNCTION__, port->number);
 
-        if (urb->status) {
-                dbg("%s - nonzero read status received: %d", __FUNCTION__,
-                                urb->status);
+        switch (urb->status) {
+        case 0: /* success */
+                break;
+        case -ECONNRESET:
+        case -ENOENT:
+        case -ESHUTDOWN:
+                /* precursor to disconnect so just go away */
+                return;
+        case -EPIPE:
+                usb_clear_halt(port->serial->dev,0x81);
+                break;
+        default:
+                /* something ugly is going on... */
+                dev_err(&urb->dev->dev,"%s - unexpected nonzero read status received: %d\n",
+                        __FUNCTION__,urb->status);
+                cypress_set_dead(port);
                 return;
         }
 
@@ -1354,7 +1406,7 @@ continue_read:
 
         /* Continue trying to always read... unless the port has closed. */
 
-        if (port->open_count > 0) {
+        if (port->open_count > 0 && priv->comm_is_ok) {
                 usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
                                 usb_rcvintpipe(port->serial->dev,
                                         port->interrupt_in_endpointAddress),
@@ -1362,10 +1414,12 @@ continue_read:
                                 port->interrupt_in_urb->transfer_buffer_length,
                                 cypress_read_int_callback, port, priv->read_urb_interval);
                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
-                if (result)
+                if (result) {
                         dev_err(&urb->dev->dev, "%s - failed resubmitting "
                                         "read urb, error %d\n", __FUNCTION__,
                                         result);
+                        cypress_set_dead(port);
+                }
         }
 
         return;
@@ -1391,20 +1445,26 @@ static void cypress_write_int_callback(struct urb *urb, struct pt_regs *regs)
                         dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
                         priv->write_urb_in_use = 0;
                         return;
-                case -EPIPE: /* no break needed */
+                case -EPIPE: /* no break needed; clear halt and resubmit */
+                        if (!priv->comm_is_ok)
+                                break;
                         usb_clear_halt(port->serial->dev, 0x02);
-                default:
                         /* error in the urb, so we have to resubmit it */
-                        dbg("%s - Overflow in write", __FUNCTION__);
                         dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
                         port->interrupt_out_urb->transfer_buffer_length = 1;
                         port->interrupt_out_urb->dev = port->serial->dev;
                         result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
-                        if (result)
-                                dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
-                                        __FUNCTION__, result);
-                        else
+                        if (!result)
                                 return;
+                        dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
+                                __FUNCTION__, result);
+                        cypress_set_dead(port);
+                        break;
+                default:
+                        dev_err(&urb->dev->dev,"%s - unexpected nonzero write status received: %d\n",
+                                __FUNCTION__,urb->status);
+                        cypress_set_dead(port);
+                        break;
         }
         
         priv->write_urb_in_use = 0;