USB: pl2303: switch to generic write implementation

Replace custom fifo-based write implementation with the generic
kfifo-based one.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 326 deletions

diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 77e968045f7..28037c1af93 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -40,16 +40,6 @@ static int debug;
 
 #define PL2303_CLOSING_WAIT     (30*HZ)
 
-#define PL2303_BUF_SIZE         1024
-#define PL2303_TMP_BUF_SIZE     1024
-
-struct pl2303_buf {
-        unsigned int    buf_size;
-        char            *buf_buf;
-        char            *buf_get;
-        char            *buf_put;
-};
-
 static const struct usb_device_id id_table[] = {
         { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID) },
         { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
@@ -157,173 +147,12 @@ enum pl2303_type {
 
 struct pl2303_private {
         spinlock_t lock;
-        struct pl2303_buf *buf;
-        int write_urb_in_use;
         wait_queue_head_t delta_msr_wait;
         u8 line_control;
         u8 line_status;
         enum pl2303_type type;
 };
 
-/*
- * pl2303_buf_alloc
- *
- * Allocate a circular buffer and all associated memory.
- */
-static struct pl2303_buf *pl2303_buf_alloc(unsigned int size)
-{
-        struct pl2303_buf *pb;
-
-        if (size == 0)
-                return NULL;
-
-        pb = kmalloc(sizeof(struct pl2303_buf), GFP_KERNEL);
-        if (pb == NULL)
-                return NULL;
-
-        pb->buf_buf = kmalloc(size, GFP_KERNEL);
-        if (pb->buf_buf == NULL) {
-                kfree(pb);
-                return NULL;
-        }
-
-        pb->buf_size = size;
-        pb->buf_get = pb->buf_put = pb->buf_buf;
-
-        return pb;
-}
-
-/*
- * pl2303_buf_free
- *
- * Free the buffer and all associated memory.
- */
-static void pl2303_buf_free(struct pl2303_buf *pb)
-{
-        if (pb) {
-                kfree(pb->buf_buf);
-                kfree(pb);
-        }
-}
-
-/*
- * pl2303_buf_clear
- *
- * Clear out all data in the circular buffer.
- */
-static void pl2303_buf_clear(struct pl2303_buf *pb)
-{
-        if (pb != NULL)
-                pb->buf_get = pb->buf_put;
-                /* equivalent to a get of all data available */
-}
-
-/*
- * pl2303_buf_data_avail
- *
- * Return the number of bytes of data available in the circular
- * buffer.
- */
-static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb)
-{
-        if (pb == NULL)
-                return 0;
-
-        return (pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size;
-}
-
-/*
- * pl2303_buf_space_avail
- *
- * Return the number of bytes of space available in the circular
- * buffer.
- */
-static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb)
-{
-        if (pb == NULL)
-                return 0;
-
-        return (pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size;
-}
-
-/*
- * pl2303_buf_put
- *
- * Copy data data from a user buffer and put it into the circular buffer.
- * Restrict to the amount of space available.
- *
- * Return the number of bytes copied.
- */
-static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,
-                                   unsigned int count)
-{
-        unsigned int len;
-
-        if (pb == NULL)
-                return 0;
-
-        len  = pl2303_buf_space_avail(pb);
-        if (count > len)
-                count = len;
-
-        if (count == 0)
-                return 0;
-
-        len = pb->buf_buf + pb->buf_size - pb->buf_put;
-        if (count > len) {
-                memcpy(pb->buf_put, buf, len);
-                memcpy(pb->buf_buf, buf+len, count - len);
-                pb->buf_put = pb->buf_buf + count - len;
-        } else {
-                memcpy(pb->buf_put, buf, count);
-                if (count < len)
-                        pb->buf_put += count;
-                else /* count == len */
-                        pb->buf_put = pb->buf_buf;
-        }
-
-        return count;
-}
-
-/*
- * pl2303_buf_get
- *
- * Get data from the circular buffer and copy to the given buffer.
- * Restrict to the amount of data available.
- *
- * Return the number of bytes copied.
- */
-static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,
-                                   unsigned int count)
-{
-        unsigned int len;
-
-        if (pb == NULL)
-                return 0;
-
-        len = pl2303_buf_data_avail(pb);
-        if (count > len)
-                count = len;
-
-        if (count == 0)
-                return 0;
-
-        len = pb->buf_buf + pb->buf_size - pb->buf_get;
-        if (count > len) {
-                memcpy(buf, pb->buf_get, len);
-                memcpy(buf+len, pb->buf_buf, count - len);
-                pb->buf_get = pb->buf_buf + count - len;
-        } else {
-                memcpy(buf, pb->buf_get, count);
-                if (count < len)
-                        pb->buf_get += count;
-                else /* count == len */
-                        pb->buf_get = pb->buf_buf;
-        }
-
-        return count;
-}
-
 static int pl2303_vendor_read(__u16 value, __u16 index,
                 struct usb_serial *serial, unsigned char *buf)
 {
@@ -372,11 +201,6 @@ static int pl2303_startup(struct usb_serial *serial)
                 if (!priv)
                         goto cleanup;
                 spin_lock_init(&priv->lock);
-                priv->buf = pl2303_buf_alloc(PL2303_BUF_SIZE);
-                if (priv->buf == NULL) {
-                        kfree(priv);
-                        goto cleanup;
-                }
                 init_waitqueue_head(&priv->delta_msr_wait);
                 priv->type = type;
                 usb_set_serial_port_data(serial->port[i], priv);
@@ -404,7 +228,6 @@ cleanup:
         kfree(buf);
         for (--i; i >= 0; --i) {
                 priv = usb_get_serial_port_data(serial->port[i]);
-                pl2303_buf_free(priv->buf);
                 kfree(priv);
                 usb_set_serial_port_data(serial->port[i], NULL);
         }
@@ -422,102 +245,6 @@ static int set_control_lines(struct usb_device *dev, u8 value)
         return retval;
 }
 
-static void pl2303_send(struct usb_serial_port *port)
-{
-        int count, result;
-        struct pl2303_private *priv = usb_get_serial_port_data(port);
-        unsigned long flags;
-
-        dbg("%s - port %d", __func__, port->number);
-
-        spin_lock_irqsave(&priv->lock, flags);
-
-        if (priv->write_urb_in_use) {
-                spin_unlock_irqrestore(&priv->lock, flags);
-                return;
-        }
-
-        count = pl2303_buf_get(priv->buf, port->write_urb->transfer_buffer,
-                               port->bulk_out_size);
-
-        if (count == 0) {
-                spin_unlock_irqrestore(&priv->lock, flags);
-                return;
-        }
-
-        priv->write_urb_in_use = 1;
-
-        spin_unlock_irqrestore(&priv->lock, flags);
-
-        usb_serial_debug_data(debug, &port->dev, __func__, count,
-                              port->write_urb->transfer_buffer);
-
-        port->write_urb->transfer_buffer_length = count;
-        result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
-        if (result) {
-                dev_err(&port->dev, "%s - failed submitting write urb,"
-                        " error %d\n", __func__, result);
-                priv->write_urb_in_use = 0;
-                /* TODO: reschedule pl2303_send */
-        }
-
-        usb_serial_port_softint(port);
-}
-
-static int pl2303_write(struct tty_struct *tty, struct usb_serial_port *port,
-                                const unsigned char *buf, int count)
-{
-        struct pl2303_private *priv = usb_get_serial_port_data(port);
-        unsigned long flags;
-
-        dbg("%s - port %d, %d bytes", __func__, port->number, count);
-
-        if (!count)
-                return count;
-
-        spin_lock_irqsave(&priv->lock, flags);
-        count = pl2303_buf_put(priv->buf, buf, count);
-        spin_unlock_irqrestore(&priv->lock, flags);
-
-        pl2303_send(port);
-
-        return count;
-}
-
-static int pl2303_write_room(struct tty_struct *tty)
-{
-        struct usb_serial_port *port = tty->driver_data;
-        struct pl2303_private *priv = usb_get_serial_port_data(port);
-        int room = 0;
-        unsigned long flags;
-
-        dbg("%s - port %d", __func__, port->number);
-
-        spin_lock_irqsave(&priv->lock, flags);
-        room = pl2303_buf_space_avail(priv->buf);
-        spin_unlock_irqrestore(&priv->lock, flags);
-
-        dbg("%s - returns %d", __func__, room);
-        return room;
-}
-
-static int pl2303_chars_in_buffer(struct tty_struct *tty)
-{
-        struct usb_serial_port *port = tty->driver_data;
-        struct pl2303_private *priv = usb_get_serial_port_data(port);
-        int chars = 0;
-        unsigned long flags;
-
-        dbg("%s - port %d", __func__, port->number);
-
-        spin_lock_irqsave(&priv->lock, flags);
-        chars = pl2303_buf_data_avail(priv->buf);
-        spin_unlock_irqrestore(&priv->lock, flags);
-
-        dbg("%s - returns %d", __func__, chars);
-        return chars;
-}
-
 static void pl2303_set_termios(struct tty_struct *tty,
                 struct usb_serial_port *port, struct ktermios *old_termios)
 {
@@ -729,15 +456,14 @@ static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
 
 static void pl2303_close(struct usb_serial_port *port)
 {
-        struct pl2303_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
 
         dbg("%s - port %d", __func__, port->number);
 
-        spin_lock_irqsave(&priv->lock, flags);
+        spin_lock_irqsave(&port->lock, flags);
         /* clear out any remaining data in the buffer */
-        pl2303_buf_clear(priv->buf);
-        spin_unlock_irqrestore(&priv->lock, flags);
+        kfifo_reset_out(&port->write_fifo);
+        spin_unlock_irqrestore(&port->lock, flags);
 
         /* shutdown our urbs */
         dbg("%s - shutting down urbs", __func__);
@@ -951,10 +677,7 @@ static void pl2303_release(struct usb_serial *serial)
 
         for (i = 0; i < serial->num_ports; ++i) {
                 priv = usb_get_serial_port_data(serial->port[i]);
-                if (priv) {
-                        pl2303_buf_free(priv->buf);
-                        kfree(priv);
-                }
+                kfree(priv);
         }
 }
 
@@ -1086,47 +809,6 @@ static void pl2303_process_read_urb(struct urb *urb)
         tty_kref_put(tty);
 }
 
-static void pl2303_write_bulk_callback(struct urb *urb)
-{
-        struct usb_serial_port *port =  urb->context;
-        struct pl2303_private *priv = usb_get_serial_port_data(port);
-        int result;
-        int status = urb->status;
-
-        dbg("%s - port %d", __func__, port->number);
-
-        switch (status) {
-        case 0:
-                /* success */
-                break;
-        case -ECONNRESET:
-        case -ENOENT:
-        case -ESHUTDOWN:
-                /* this urb is terminated, clean up */
-                dbg("%s - urb shutting down with status: %d", __func__,
-                    status);
-                priv->write_urb_in_use = 0;
-                return;
-        default:
-                /* error in the urb, so we have to resubmit it */
-                dbg("%s - Overflow in write", __func__);
-                dbg("%s - nonzero write bulk status received: %d", __func__,
-                    status);
-                port->write_urb->transfer_buffer_length = 1;
-                result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
-                if (result)
-                        dev_err(&urb->dev->dev, "%s - failed resubmitting write"
-                                " urb, error %d\n", __func__, result);
-                else
-                        return;
-        }
-
-        priv->write_urb_in_use = 0;
-
-        /* send any buffered data */
-        pl2303_send(port);
-}
-
 /* All of the device info needed for the PL2303 SIO serial converter */
 static struct usb_serial_driver pl2303_device = {
         .driver = {
@@ -1142,7 +824,6 @@ static struct usb_serial_driver pl2303_device = {
         .close =                pl2303_close,
         .dtr_rts =              pl2303_dtr_rts,
         .carrier_raised =       pl2303_carrier_raised,
-        .write =                pl2303_write,
         .ioctl =                pl2303_ioctl,
         .break_ctl =            pl2303_break_ctl,
         .set_termios =          pl2303_set_termios,
@@ -1150,9 +831,6 @@ static struct usb_serial_driver pl2303_device = {
         .tiocmset =             pl2303_tiocmset,
         .process_read_urb =     pl2303_process_read_urb,
         .read_int_callback =    pl2303_read_int_callback,
-        .write_bulk_callback =  pl2303_write_bulk_callback,
-        .write_room =           pl2303_write_room,
-        .chars_in_buffer =      pl2303_chars_in_buffer,
         .attach =               pl2303_startup,
         .release =              pl2303_release,
 };