USB: garmin_gps: removes usb_reset_device from garmin_close

The following patch removes the call to usb_reset_device which may occur
when closing the driver by implementing a new session initialization
code based on the method used by gpsbabel.

The patch is against  linux-2.6.30-rc3-git1.

Signed-off-by: Hermann Kneissel herkne@users.sourceforge.net
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 73 insertions, 125 deletions

diff --git a/drivers/usb/serial/garmin_gps.c b/drivers/usb/serial/garmin_gps.c
index ee25a3fe3b09..5092d6aba659 100644
--- a/drivers/usb/serial/garmin_gps.c
+++ b/drivers/usb/serial/garmin_gps.c
@@ -1,7 +1,7 @@
 /*
  * Garmin GPS driver
  *
- * Copyright (C) 2006,2007 Hermann Kneissel herkne@users.sourceforge.net
+ * Copyright (C) 2006-2009 Hermann Kneissel herkne@users.sourceforge.net
  *
  * The latest version of the driver can be found at
  * http://sourceforge.net/projects/garmin-gps/
@@ -51,7 +51,7 @@ static int debug;
  */
 
 #define VERSION_MAJOR   0
-#define VERSION_MINOR   31
+#define VERSION_MINOR   33
 
 #define _STR(s) #s
 #define _DRIVER_VERSION(a, b) "v" _STR(a) "." _STR(b)
@@ -129,7 +129,6 @@ struct garmin_data {
         __u8   state;
         __u16  flags;
         __u8   mode;
-        __u8   ignorePkts;
         __u8   count;
         __u8   pkt_id;
         __u32  serial_num;
@@ -141,8 +140,6 @@ struct garmin_data {
         __u8   inbuffer [GPS_IN_BUFSIZ];  /* tty -> usb */
         __u8   outbuffer[GPS_OUT_BUFSIZ]; /* usb -> tty */
         __u8   privpkt[4*6];
-        atomic_t req_count;
-        atomic_t resp_count;
         spinlock_t lock;
         struct list_head pktlist;
 };
@@ -170,6 +167,8 @@ struct garmin_data {
 #define FLAGS_BULK_IN_ACTIVE      0x0020
 #define FLAGS_BULK_IN_RESTART     0x0010
 #define FLAGS_THROTTLED           0x0008
+#define APP_REQ_SEEN              0x0004
+#define APP_RESP_SEEN             0x0002
 #define CLEAR_HALT_REQUIRED       0x0001
 
 #define FLAGS_QUEUING             0x0100
@@ -184,20 +183,16 @@ struct garmin_data {
 
 
 /* function prototypes */
-static void gsp_next_packet(struct garmin_data *garmin_data_p);
-static int  garmin_write_bulk(struct usb_serial_port *port,
+static int gsp_next_packet(struct garmin_data *garmin_data_p);
+static int garmin_write_bulk(struct usb_serial_port *port,
                              const unsigned char *buf, int count,
                              int dismiss_ack);
 
 /* some special packets to be send or received */
 static unsigned char const GARMIN_START_SESSION_REQ[]
         = { 0, 0, 0, 0,  5, 0, 0, 0, 0, 0, 0, 0 };
-static unsigned char const GARMIN_START_SESSION_REQ2[]
-        = { 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0 };
 static unsigned char const GARMIN_START_SESSION_REPLY[]
         = { 0, 0, 0, 0,  6, 0, 0, 0, 4, 0, 0, 0 };
-static unsigned char const GARMIN_SESSION_ACTIVE_REPLY[]
-        = { 0, 0, 0, 0, 17, 0, 0, 0, 4, 0, 0, 0, 0, 16, 0, 0 };
 static unsigned char const GARMIN_BULK_IN_AVAIL_REPLY[]
         = { 0, 0, 0, 0,  2, 0, 0, 0, 0, 0, 0, 0 };
 static unsigned char const GARMIN_APP_LAYER_REPLY[]
@@ -233,13 +228,6 @@ static struct usb_driver garmin_driver = {
 };
 
 
-static inline int noResponseFromAppLayer(struct garmin_data *garmin_data_p)
-{
-        return atomic_read(&garmin_data_p->req_count) ==
-                                atomic_read(&garmin_data_p->resp_count);
-}
-
-
 static inline int getLayerId(const __u8 *usbPacket)
 {
         return __le32_to_cpup((__le32 *)(usbPacket));
@@ -325,8 +313,11 @@ static int pkt_add(struct garmin_data *garmin_data_p,
                 state = garmin_data_p->state;
                 spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 
+                dbg("%s - added: pkt: %d - %d bytes",
+                        __func__, pkt->seq, data_length);
+
                 /* in serial mode, if someone is waiting for data from
-                   the device, iconvert and send the next packet to tty. */
+                   the device, convert and send the next packet to tty. */
                 if (result && (state == STATE_GSP_WAIT_DATA))
                         gsp_next_packet(garmin_data_p);
         }
@@ -411,7 +402,7 @@ static int gsp_send_ack(struct garmin_data *garmin_data_p, __u8 pkt_id)
 /*
  * called for a complete packet received from tty layer
  *
- * the complete packet (pkzid ... cksum) is in garmin_data_p->inbuf starting
+ * the complete packet (pktid ... cksum) is in garmin_data_p->inbuf starting
  * at GSP_INITIAL_OFFSET.
  *
  * count - number of bytes in the input buffer including space reserved for
@@ -501,7 +492,6 @@ static int gsp_receive(struct garmin_data *garmin_data_p,
         unsigned long flags;
         int offs = 0;
         int ack_or_nak_seen = 0;
-        int i = 0;
         __u8 *dest;
         int size;
         /* dleSeen: set if last byte read was a DLE */
@@ -519,8 +509,8 @@ static int gsp_receive(struct garmin_data *garmin_data_p,
         skip = garmin_data_p->flags & FLAGS_GSP_SKIP;
         spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 
-        dbg("%s - dle=%d skip=%d size=%d count=%d",
-                __func__, dleSeen, skip, size, count);
+        /* dbg("%s - dle=%d skip=%d size=%d count=%d",
+                __func__, dleSeen, skip, size, count); */
 
         if (size == 0)
                 size = GSP_INITIAL_OFFSET;
@@ -568,7 +558,6 @@ static int gsp_receive(struct garmin_data *garmin_data_p,
                 } else if (!skip) {
 
                         if (dleSeen) {
-                                dbg("non-masked DLE at %d - restarting", i);
                                 size = GSP_INITIAL_OFFSET;
                                 dleSeen = 0;
                         }
@@ -599,19 +588,19 @@ static int gsp_receive(struct garmin_data *garmin_data_p,
         else
                 garmin_data_p->flags &= ~FLAGS_GSP_DLESEEN;
 
-        if (ack_or_nak_seen)
-                garmin_data_p->state = STATE_GSP_WAIT_DATA;
-
         spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 
-        if (ack_or_nak_seen)
-                gsp_next_packet(garmin_data_p);
+        if (ack_or_nak_seen) {
+                if (gsp_next_packet(garmin_data_p) > 0)
+                        garmin_data_p->state = STATE_ACTIVE;
+                else
+                        garmin_data_p->state = STATE_GSP_WAIT_DATA;
+        }
         return count;
 }
 
 
 
-
 /*
  * Sends a usb packet to the tty
  *
@@ -733,29 +722,28 @@ static int gsp_send(struct garmin_data *garmin_data_p,
 }
 
 
-
-
-
 /*
  * Process the next pending data packet - if there is one
  */
-static void gsp_next_packet(struct garmin_data *garmin_data_p)
+static int gsp_next_packet(struct garmin_data *garmin_data_p)
 {
+        int result = 0;
         struct garmin_packet *pkt = NULL;
 
         while ((pkt = pkt_pop(garmin_data_p)) != NULL) {
                 dbg("%s - next pkt: %d", __func__, pkt->seq);
-                if (gsp_send(garmin_data_p, pkt->data, pkt->size) > 0) {
+                result = gsp_send(garmin_data_p, pkt->data, pkt->size);
+                if (result > 0) {
                         kfree(pkt);
-                        return;
+                        return result;
                 }
                 kfree(pkt);
         }
+        return result;
 }
 
 
 
-
 /******************************************************************************
  * garmin native mode
  ******************************************************************************/
@@ -888,14 +876,6 @@ static int garmin_clear(struct garmin_data *garmin_data_p)
         unsigned long flags;
         int status = 0;
 
-        struct usb_serial_port *port = garmin_data_p->port;
-
-        if (port != NULL && atomic_read(&garmin_data_p->resp_count)) {
-                /* send a terminate command */
-                status = garmin_write_bulk(port, GARMIN_STOP_TRANSFER_REQ,
-                                        sizeof(GARMIN_STOP_TRANSFER_REQ), 1);
-        }
-
         /* flush all queued data */
         pkt_clear(garmin_data_p);
 
@@ -908,16 +888,12 @@ static int garmin_clear(struct garmin_data *garmin_data_p)
 }
 
 
-
-
-
-
 static int garmin_init_session(struct usb_serial_port *port)
 {
-        unsigned long flags;
         struct usb_serial *serial = port->serial;
         struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
         int status = 0;
+        int i = 0;
 
         if (status == 0) {
                 usb_kill_urb(port->interrupt_in_urb);
@@ -931,30 +907,25 @@ static int garmin_init_session(struct usb_serial_port *port)
                                                         __func__, status);
         }
 
+        /*
+         * using the initialization method from gpsbabel. See comments in
+         * gpsbabel/jeeps/gpslibusb.c gusb_reset_toggles()
+         */
         if (status == 0) {
                 dbg("%s - starting session ...", __func__);
                 garmin_data_p->state = STATE_ACTIVE;
-                status = garmin_write_bulk(port, GARMIN_START_SESSION_REQ,
-                                        sizeof(GARMIN_START_SESSION_REQ), 0);
 
-                if (status >= 0) {
-
-                        spin_lock_irqsave(&garmin_data_p->lock, flags);
-                        garmin_data_p->ignorePkts++;
-                        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
-
-                        /* not needed, but the win32 driver does it too ... */
+                for (i = 0; i < 3; i++) {
                         status = garmin_write_bulk(port,
-                                        GARMIN_START_SESSION_REQ2,
-                                        sizeof(GARMIN_START_SESSION_REQ2), 0);
-                        if (status >= 0) {
-                                status = 0;
-                                spin_lock_irqsave(&garmin_data_p->lock, flags);
-                                garmin_data_p->ignorePkts++;
-                                spin_unlock_irqrestore(&garmin_data_p->lock,
-                                                                        flags);
-                        }
+                                        GARMIN_START_SESSION_REQ,
+                                        sizeof(GARMIN_START_SESSION_REQ), 0);
+
+                        if (status < 0)
+                                break;
                 }
+
+                if (status > 0)
+                        status = 0;
         }
 
         return status;
@@ -962,8 +933,6 @@ static int garmin_init_session(struct usb_serial_port *port)
 
 
 
-
-
 static int garmin_open(struct tty_struct *tty,
                         struct usb_serial_port *port, struct file *filp)
 {
@@ -977,8 +946,6 @@ static int garmin_open(struct tty_struct *tty,
         garmin_data_p->mode  = initial_mode;
         garmin_data_p->count = 0;
         garmin_data_p->flags = 0;
-        atomic_set(&garmin_data_p->req_count, 0);
-        atomic_set(&garmin_data_p->resp_count, 0);
         spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 
         /* shutdown any bulk reads that might be going on */
@@ -1006,6 +973,7 @@ static void garmin_close(struct usb_serial_port *port)
                 return;
 
         mutex_lock(&port->serial->disc_mutex);
+
         if (!port->serial->disconnected)
                 garmin_clear(garmin_data_p);
 
@@ -1013,25 +981,17 @@ static void garmin_close(struct usb_serial_port *port)
         usb_kill_urb(port->read_urb);
         usb_kill_urb(port->write_urb);
 
-        if (!port->serial->disconnected) {
-                if (noResponseFromAppLayer(garmin_data_p) ||
-                    ((garmin_data_p->flags & CLEAR_HALT_REQUIRED) != 0)) {
-                        process_resetdev_request(port);
-                        garmin_data_p->state = STATE_RESET;
-                } else {
-                        garmin_data_p->state = STATE_DISCONNECTED;
-                }
-        } else {
+        /* keep reset state so we know that we must start a new session */
+        if (garmin_data_p->state != STATE_RESET)
                 garmin_data_p->state = STATE_DISCONNECTED;
-        }
+
         mutex_unlock(&port->serial->disc_mutex);
 }
 
+
 static void garmin_write_bulk_callback(struct urb *urb)
 {
-        unsigned long flags;
         struct usb_serial_port *port = urb->context;
-        int status = urb->status;
 
         if (port) {
                 struct garmin_data *garmin_data_p =
@@ -1039,20 +999,13 @@ static void garmin_write_bulk_callback(struct urb *urb)
 
                 dbg("%s - port %d", __func__, port->number);
 
-                if (GARMIN_LAYERID_APPL == getLayerId(urb->transfer_buffer)
-                    && (garmin_data_p->mode == MODE_GARMIN_SERIAL))  {
-                        gsp_send_ack(garmin_data_p,
-                                        ((__u8 *)urb->transfer_buffer)[4]);
-                }
+                if (GARMIN_LAYERID_APPL == getLayerId(urb->transfer_buffer)) {
 
-                if (status) {
-                        dbg("%s - nonzero write bulk status received: %d",
-                            __func__, status);
-                        spin_lock_irqsave(&garmin_data_p->lock, flags);
-                        garmin_data_p->flags |= CLEAR_HALT_REQUIRED;
-                        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
+                        if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
+                                gsp_send_ack(garmin_data_p,
+                                        ((__u8 *)urb->transfer_buffer)[4]);
+                        }
                 }
-
                 usb_serial_port_softint(port);
         }
 
@@ -1108,7 +1061,11 @@ static int garmin_write_bulk(struct usb_serial_port *port,
         urb->transfer_flags |= URB_ZERO_PACKET;
 
         if (GARMIN_LAYERID_APPL == getLayerId(buffer)) {
-                atomic_inc(&garmin_data_p->req_count);
+
+                spin_lock_irqsave(&garmin_data_p->lock, flags);
+                garmin_data_p->flags |= APP_REQ_SEEN;
+                spin_unlock_irqrestore(&garmin_data_p->lock, flags);
+
                 if (garmin_data_p->mode == MODE_GARMIN_SERIAL)  {
                         pkt_clear(garmin_data_p);
                         garmin_data_p->state = STATE_GSP_WAIT_DATA;
@@ -1140,6 +1097,9 @@ static int garmin_write(struct tty_struct *tty, struct usb_serial_port *port,
 
         usb_serial_debug_data(debug, &port->dev, __func__, count, buf);
 
+        if (garmin_data_p->state == STATE_RESET)
+                return -EIO;
+
         /* check for our private packets */
         if (count >= GARMIN_PKTHDR_LENGTH) {
                 len = PRIVPKTSIZ;
@@ -1184,7 +1144,7 @@ static int garmin_write(struct tty_struct *tty, struct usb_serial_port *port,
                                 break;
 
                         case PRIV_PKTID_RESET_REQ:
-                                atomic_inc(&garmin_data_p->req_count);
+                                process_resetdev_request(port);
                                 break;
 
                         case PRIV_PKTID_SET_DEF_MODE:
@@ -1200,8 +1160,6 @@ static int garmin_write(struct tty_struct *tty, struct usb_serial_port *port,
                 }
         }
 
-        garmin_data_p->ignorePkts = 0;
-
         if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
                 return gsp_receive(garmin_data_p, buf, count);
         } else {        /* MODE_NATIVE */
@@ -1224,31 +1182,33 @@ static int garmin_write_room(struct tty_struct *tty)
 static void garmin_read_process(struct garmin_data *garmin_data_p,
                                  unsigned char *data, unsigned data_length)
 {
+        unsigned long flags;
+
         if (garmin_data_p->flags & FLAGS_DROP_DATA) {
                 /* abort-transfer cmd is actice */
                 dbg("%s - pkt dropped", __func__);
         } else if (garmin_data_p->state != STATE_DISCONNECTED &&
                 garmin_data_p->state != STATE_RESET) {
 
-                /* remember any appl.layer packets, so we know
-                   if a reset is required or not when closing
-                   the device */
-                if (0 == memcmp(data, GARMIN_APP_LAYER_REPLY,
-                                sizeof(GARMIN_APP_LAYER_REPLY))) {
-                        atomic_inc(&garmin_data_p->resp_count);
-                }
-
                 /* if throttling is active or postprecessing is required
                    put the received data in the input queue, otherwise
                    send it directly to the tty port */
                 if (garmin_data_p->flags & FLAGS_QUEUING) {
                         pkt_add(garmin_data_p, data, data_length);
-                } else if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
-                        if (getLayerId(data) == GARMIN_LAYERID_APPL)
+                } else if (getLayerId(data) == GARMIN_LAYERID_APPL) {
+
+                        spin_lock_irqsave(&garmin_data_p->lock, flags);
+                        garmin_data_p->flags |= APP_RESP_SEEN;
+                        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
+
+                        if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
                                 pkt_add(garmin_data_p, data, data_length);
-                } else {
-                        send_to_tty(garmin_data_p->port, data, data_length);
+                        } else {
+                                send_to_tty(garmin_data_p->port, data,
+                                                data_length);
+                        }
                 }
+                /* ignore system layer packets ... */
         }
 }
 
@@ -1363,8 +1323,6 @@ static void garmin_read_int_callback(struct urb *urb)
                         } else {
                                 spin_lock_irqsave(&garmin_data_p->lock, flags);
                                 garmin_data_p->flags |= FLAGS_BULK_IN_ACTIVE;
-                                /* do not send this packet to the user */
-                                garmin_data_p->ignorePkts = 1;
                                 spin_unlock_irqrestore(&garmin_data_p->lock,
                                                                         flags);
                         }
@@ -1391,17 +1349,7 @@ static void garmin_read_int_callback(struct urb *urb)
                         __func__, garmin_data_p->serial_num);
         }
 
-        if (garmin_data_p->ignorePkts) {
-                /* this reply belongs to a request generated by the driver,
-                   ignore it. */
-                dbg("%s - pkt ignored (%d)",
-                        __func__, garmin_data_p->ignorePkts);
-                spin_lock_irqsave(&garmin_data_p->lock, flags);
-                garmin_data_p->ignorePkts--;
-                spin_unlock_irqrestore(&garmin_data_p->lock, flags);
-        } else {
-                garmin_read_process(garmin_data_p, data, urb->actual_length);
-        }
+        garmin_read_process(garmin_data_p, data, urb->actual_length);
 
         port->interrupt_in_urb->dev = port->serial->dev;
         retval = usb_submit_urb(urb, GFP_ATOMIC);