From: Johan Hovold Date: Sun, 16 May 2010 18:33:50 +0000 (+0200) Subject: USB: cypress_m8: use kfifo to implement write buffering X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=117fb8d086cfc6e51c729fe5533bb83cb55c150a;p=linux-beck.git USB: cypress_m8: use kfifo to implement write buffering Kill custom fifo implementation. Note that cypress_m8 has no port write fifo as it has no bulk-out endpoint. Compile-only tested. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c index d96374865289..f5d06746cc3b 100644 --- a/drivers/usb/serial/cypress_m8.c +++ b/drivers/usb/serial/cypress_m8.c @@ -64,6 +64,7 @@ #include #include #include +#include #include #include #include @@ -79,7 +80,7 @@ static int unstable_bauds; /* * Version Information */ -#define DRIVER_VERSION "v1.09" +#define DRIVER_VERSION "v1.10" #define DRIVER_AUTHOR "Lonnie Mendez , Neil Whelchel " #define DRIVER_DESC "Cypress USB to Serial Driver" @@ -134,7 +135,7 @@ struct cypress_private { int bytes_out; /* used for statistics */ int cmd_count; /* used for statistics */ int cmd_ctrl; /* always set this to 1 before issuing a command */ - struct cypress_buf *buf; /* write buffer */ + struct kfifo write_fifo; /* write fifo */ 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 */ @@ -156,14 +157,6 @@ struct cypress_private { struct ktermios tmp_termios; /* stores the old termios settings */ }; -/* write buffer structure */ -struct cypress_buf { - unsigned int buf_size; - char *buf_buf; - char *buf_get; - char *buf_put; -}; - /* function prototypes for the Cypress USB to serial device */ static int cypress_earthmate_startup(struct usb_serial *serial); static int cypress_hidcom_startup(struct usb_serial *serial); @@ -189,17 +182,6 @@ static void cypress_unthrottle(struct tty_struct *tty); static void cypress_set_dead(struct usb_serial_port *port); static void cypress_read_int_callback(struct urb *urb); static void cypress_write_int_callback(struct urb *urb); -/* write buffer functions */ -static struct cypress_buf *cypress_buf_alloc(unsigned int size); -static void cypress_buf_free(struct cypress_buf *cb); -static void cypress_buf_clear(struct cypress_buf *cb); -static unsigned int cypress_buf_data_avail(struct cypress_buf *cb); -static unsigned int cypress_buf_space_avail(struct cypress_buf *cb); -static unsigned int cypress_buf_put(struct cypress_buf *cb, - const char *buf, unsigned int count); -static unsigned int cypress_buf_get(struct cypress_buf *cb, - char *buf, unsigned int count); - static struct usb_serial_driver cypress_earthmate_device = { .driver = { @@ -502,8 +484,7 @@ static int generic_startup(struct usb_serial *serial) priv->comm_is_ok = !0; spin_lock_init(&priv->lock); - priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE); - if (priv->buf == NULL) { + if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) { kfree(priv); return -ENOMEM; } @@ -626,7 +607,7 @@ static void cypress_release(struct usb_serial *serial) priv = usb_get_serial_port_data(serial->port[0]); if (priv) { - cypress_buf_free(priv->buf); + kfifo_free(&priv->write_fifo); kfree(priv); } } @@ -703,6 +684,7 @@ static void cypress_dtr_rts(struct usb_serial_port *port, int on) static void cypress_close(struct usb_serial_port *port) { struct cypress_private *priv = usb_get_serial_port_data(port); + unsigned long flags; dbg("%s - port %d", __func__, port->number); @@ -712,12 +694,14 @@ static void cypress_close(struct usb_serial_port *port) mutex_unlock(&port->serial->disc_mutex); return; } - cypress_buf_clear(priv->buf); + spin_lock_irqsave(&priv->lock, flags); + kfifo_reset_out(&priv->write_fifo); + spin_unlock_irqrestore(&priv->lock, flags); + dbg("%s - stopping urbs", __func__); usb_kill_urb(port->interrupt_in_urb); usb_kill_urb(port->interrupt_out_urb); - if (stats) dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n", priv->bytes_in, priv->bytes_out, priv->cmd_count); @@ -729,7 +713,6 @@ static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *buf, int count) { struct cypress_private *priv = usb_get_serial_port_data(port); - unsigned long flags; dbg("%s - port %d, %d bytes", __func__, port->number, count); @@ -744,9 +727,7 @@ static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port, if (!count) return count; - spin_lock_irqsave(&priv->lock, flags); - count = cypress_buf_put(priv->buf, buf, count); - spin_unlock_irqrestore(&priv->lock, flags); + count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock); finish: cypress_send(port); @@ -806,9 +787,10 @@ static void cypress_send(struct usb_serial_port *port) } else spin_unlock_irqrestore(&priv->lock, flags); - count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset], - port->interrupt_out_size-offset); - + count = kfifo_out_locked(&priv->write_fifo, + &port->interrupt_out_buffer[offset], + port->interrupt_out_size - offset, + &priv->lock); if (count == 0) return; @@ -874,7 +856,7 @@ static int cypress_write_room(struct tty_struct *tty) dbg("%s - port %d", __func__, port->number); spin_lock_irqsave(&priv->lock, flags); - room = cypress_buf_space_avail(priv->buf); + room = kfifo_avail(&priv->write_fifo); spin_unlock_irqrestore(&priv->lock, flags); dbg("%s - returns %d", __func__, room); @@ -1142,7 +1124,7 @@ static int cypress_chars_in_buffer(struct tty_struct *tty) dbg("%s - port %d", __func__, port->number); spin_lock_irqsave(&priv->lock, flags); - chars = cypress_buf_data_avail(priv->buf); + chars = kfifo_len(&priv->write_fifo); spin_unlock_irqrestore(&priv->lock, flags); dbg("%s - returns %d", __func__, chars); @@ -1395,193 +1377,6 @@ static void cypress_write_int_callback(struct urb *urb) } -/***************************************************************************** - * Write buffer functions - buffering code from pl2303 used - *****************************************************************************/ - -/* - * cypress_buf_alloc - * - * Allocate a circular buffer and all associated memory. - */ - -static struct cypress_buf *cypress_buf_alloc(unsigned int size) -{ - - struct cypress_buf *cb; - - - if (size == 0) - return NULL; - - cb = kmalloc(sizeof(struct cypress_buf), GFP_KERNEL); - if (cb == NULL) - return NULL; - - cb->buf_buf = kmalloc(size, GFP_KERNEL); - if (cb->buf_buf == NULL) { - kfree(cb); - return NULL; - } - - cb->buf_size = size; - cb->buf_get = cb->buf_put = cb->buf_buf; - - return cb; - -} - - -/* - * cypress_buf_free - * - * Free the buffer and all associated memory. - */ - -static void cypress_buf_free(struct cypress_buf *cb) -{ - if (cb) { - kfree(cb->buf_buf); - kfree(cb); - } -} - - -/* - * cypress_buf_clear - * - * Clear out all data in the circular buffer. - */ - -static void cypress_buf_clear(struct cypress_buf *cb) -{ - if (cb != NULL) - cb->buf_get = cb->buf_put; - /* equivalent to a get of all data available */ -} - - -/* - * cypress_buf_data_avail - * - * Return the number of bytes of data available in the circular - * buffer. - */ - -static unsigned int cypress_buf_data_avail(struct cypress_buf *cb) -{ - if (cb != NULL) - return (cb->buf_size + cb->buf_put - cb->buf_get) - % cb->buf_size; - else - return 0; -} - - -/* - * cypress_buf_space_avail - * - * Return the number of bytes of space available in the circular - * buffer. - */ - -static unsigned int cypress_buf_space_avail(struct cypress_buf *cb) -{ - if (cb != NULL) - return (cb->buf_size + cb->buf_get - cb->buf_put - 1) - % cb->buf_size; - else - return 0; -} - - -/* - * cypress_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 cypress_buf_put(struct cypress_buf *cb, const char *buf, - unsigned int count) -{ - - unsigned int len; - - - if (cb == NULL) - return 0; - - len = cypress_buf_space_avail(cb); - if (count > len) - count = len; - - if (count == 0) - return 0; - - len = cb->buf_buf + cb->buf_size - cb->buf_put; - if (count > len) { - memcpy(cb->buf_put, buf, len); - memcpy(cb->buf_buf, buf+len, count - len); - cb->buf_put = cb->buf_buf + count - len; - } else { - memcpy(cb->buf_put, buf, count); - if (count < len) - cb->buf_put += count; - else /* count == len */ - cb->buf_put = cb->buf_buf; - } - - return count; - -} - - -/* - * cypress_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 cypress_buf_get(struct cypress_buf *cb, char *buf, - unsigned int count) -{ - - unsigned int len; - - - if (cb == NULL) - return 0; - - len = cypress_buf_data_avail(cb); - if (count > len) - count = len; - - if (count == 0) - return 0; - - len = cb->buf_buf + cb->buf_size - cb->buf_get; - if (count > len) { - memcpy(buf, cb->buf_get, len); - memcpy(buf+len, cb->buf_buf, count - len); - cb->buf_get = cb->buf_buf + count - len; - } else { - memcpy(buf, cb->buf_get, count); - if (count < len) - cb->buf_get += count; - else /* count == len */ - cb->buf_get = cb->buf_buf; - } - - return count; - -} - /***************************************************************************** * Module functions *****************************************************************************/