From e3c1803f8b33fb97005202fa3645501ebb946d93 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sun, 16 May 2010 20:33:51 +0200 Subject: [PATCH] USB: oti6858: use kfifo to implement write buffering Kill custom fifo implementation. Use private write fifo to minimise changes to lock handling. Compile-only tested. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/oti6858.c | 218 ++++--------------------------------------- 1 file changed, 17 insertions(+), 201 deletions(-) diff --git a/drivers/usb/serial/oti6858.c b/drivers/usb/serial/oti6858.c index 525d852..a65be37 100644 --- a/drivers/usb/serial/oti6858.c +++ b/drivers/usb/serial/oti6858.c @@ -51,12 +51,13 @@ #include #include #include +#include #include "oti6858.h" #define OTI6858_DESCRIPTION \ "Ours Technology Inc. OTi-6858 USB to serial adapter driver" #define OTI6858_AUTHOR "Tomasz Michal Lukaszewski " -#define OTI6858_VERSION "0.1" +#define OTI6858_VERSION "0.2" static const struct usb_device_id id_table[] = { { USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) }, @@ -75,17 +76,7 @@ static struct usb_driver oti6858_driver = { static int debug; - -/* buffering code, copied from pl2303 driver */ -#define PL2303_BUF_SIZE 1024 -#define PL2303_TMP_BUF_SIZE 1024 - -struct oti6858_buf { - unsigned int buf_size; - char *buf_buf; - char *buf_get; - char *buf_put; -}; +#define OTI6858_FIFO_SIZE 1024 /* requests */ #define OTI6858_REQ_GET_STATUS (USB_DIR_IN | USB_TYPE_VENDOR | 0x00) @@ -161,18 +152,6 @@ static int oti6858_tiocmset(struct tty_struct *tty, struct file *file, static int oti6858_startup(struct usb_serial *serial); static void oti6858_release(struct usb_serial *serial); -/* functions operating on buffers */ -static struct oti6858_buf *oti6858_buf_alloc(unsigned int size); -static void oti6858_buf_free(struct oti6858_buf *pb); -static void oti6858_buf_clear(struct oti6858_buf *pb); -static unsigned int oti6858_buf_data_avail(struct oti6858_buf *pb); -static unsigned int oti6858_buf_space_avail(struct oti6858_buf *pb); -static unsigned int oti6858_buf_put(struct oti6858_buf *pb, const char *buf, - unsigned int count); -static unsigned int oti6858_buf_get(struct oti6858_buf *pb, char *buf, - unsigned int count); - - /* device info */ static struct usb_serial_driver oti6858_device = { .driver = { @@ -201,7 +180,7 @@ static struct usb_serial_driver oti6858_device = { struct oti6858_private { spinlock_t lock; - struct oti6858_buf *buf; + struct kfifo write_fifo; struct oti6858_control_pkt status; struct { @@ -315,7 +294,7 @@ static void send_data(struct work_struct *work) } priv->flags.write_urb_in_use = 1; - count = oti6858_buf_data_avail(priv->buf); + count = kfifo_len(&priv->write_fifo); spin_unlock_irqrestore(&priv->lock, flags); if (count > port->bulk_out_size) count = port->bulk_out_size; @@ -350,10 +329,9 @@ static void send_data(struct work_struct *work) return; } - spin_lock_irqsave(&priv->lock, flags); - oti6858_buf_get(priv->buf, port->write_urb->transfer_buffer, count); - spin_unlock_irqrestore(&priv->lock, flags); - + count = kfifo_out_locked(&priv->write_fifo, + port->write_urb->transfer_buffer, + count, &priv->lock); port->write_urb->transfer_buffer_length = count; port->write_urb->dev = port->serial->dev; result = usb_submit_urb(port->write_urb, GFP_NOIO); @@ -376,8 +354,8 @@ static int oti6858_startup(struct usb_serial *serial) priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL); if (!priv) break; - priv->buf = oti6858_buf_alloc(PL2303_BUF_SIZE); - if (priv->buf == NULL) { + if (kfifo_alloc(&priv->write_fifo, OTI6858_FIFO_SIZE, + GFP_KERNEL)) { kfree(priv); break; } @@ -397,7 +375,7 @@ static int oti6858_startup(struct usb_serial *serial) for (--i; i >= 0; --i) { priv = usb_get_serial_port_data(serial->port[i]); - oti6858_buf_free(priv->buf); + kfifo_free(&priv->write_fifo); kfree(priv); usb_set_serial_port_data(serial->port[i], NULL); } @@ -408,16 +386,13 @@ static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *buf, int count) { struct oti6858_private *priv = usb_get_serial_port_data(port); - unsigned long flags; dbg("%s(port = %d, count = %d)", __func__, port->number, count); if (!count) return count; - spin_lock_irqsave(&priv->lock, flags); - count = oti6858_buf_put(priv->buf, buf, count); - spin_unlock_irqrestore(&priv->lock, flags); + count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock); return count; } @@ -432,7 +407,7 @@ static int oti6858_write_room(struct tty_struct *tty) dbg("%s(port = %d)", __func__, port->number); spin_lock_irqsave(&priv->lock, flags); - room = oti6858_buf_space_avail(priv->buf); + room = kfifo_avail(&priv->write_fifo); spin_unlock_irqrestore(&priv->lock, flags); return room; @@ -448,7 +423,7 @@ static int oti6858_chars_in_buffer(struct tty_struct *tty) dbg("%s(port = %d)", __func__, port->number); spin_lock_irqsave(&priv->lock, flags); - chars = oti6858_buf_data_avail(priv->buf); + chars = kfifo_len(&priv->write_fifo); spin_unlock_irqrestore(&priv->lock, flags); return chars; @@ -642,7 +617,7 @@ static void oti6858_close(struct usb_serial_port *port) spin_lock_irqsave(&priv->lock, flags); /* clear out any remaining data in the buffer */ - oti6858_buf_clear(priv->buf); + kfifo_reset_out(&priv->write_fifo); spin_unlock_irqrestore(&priv->lock, flags); dbg("%s(): after buf_clear()", __func__); @@ -793,7 +768,7 @@ static void oti6858_release(struct usb_serial *serial) for (i = 0; i < serial->num_ports; ++i) { priv = usb_get_serial_port_data(serial->port[i]); if (priv) { - oti6858_buf_free(priv->buf); + kfifo_free(&priv->write_fifo); kfree(priv); } } @@ -892,7 +867,7 @@ static void oti6858_read_int_callback(struct urb *urb) spin_lock_irqsave(&priv->lock, flags); if (priv->flags.write_urb_in_use == 0 - && oti6858_buf_data_avail(priv->buf) != 0) { + && kfifo_len(&priv->write_fifo) != 0) { schedule_delayed_work(&priv->delayed_write_work, 0); resubmit = 0; } @@ -1014,165 +989,6 @@ static void oti6858_write_bulk_callback(struct urb *urb) } } - -/* - * oti6858_buf_alloc - * - * Allocate a circular buffer and all associated memory. - */ -static struct oti6858_buf *oti6858_buf_alloc(unsigned int size) -{ - struct oti6858_buf *pb; - - if (size == 0) - return NULL; - - pb = kmalloc(sizeof(struct oti6858_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; -} - -/* - * oti6858_buf_free - * - * Free the buffer and all associated memory. - */ -static void oti6858_buf_free(struct oti6858_buf *pb) -{ - if (pb) { - kfree(pb->buf_buf); - kfree(pb); - } -} - -/* - * oti6858_buf_clear - * - * Clear out all data in the circular buffer. - */ -static void oti6858_buf_clear(struct oti6858_buf *pb) -{ - if (pb != NULL) { - /* equivalent to a get of all data available */ - pb->buf_get = pb->buf_put; - } -} - -/* - * oti6858_buf_data_avail - * - * Return the number of bytes of data available in the circular - * buffer. - */ -static unsigned int oti6858_buf_data_avail(struct oti6858_buf *pb) -{ - if (pb == NULL) - return 0; - return (pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size; -} - -/* - * oti6858_buf_space_avail - * - * Return the number of bytes of space available in the circular - * buffer. - */ -static unsigned int oti6858_buf_space_avail(struct oti6858_buf *pb) -{ - if (pb == NULL) - return 0; - return (pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size; -} - -/* - * oti6858_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 oti6858_buf_put(struct oti6858_buf *pb, const char *buf, - unsigned int count) -{ - unsigned int len; - - if (pb == NULL) - return 0; - - len = oti6858_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; -} - -/* - * oti6858_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 oti6858_buf_get(struct oti6858_buf *pb, char *buf, - unsigned int count) -{ - unsigned int len; - - if (pb == NULL) - return 0; - - len = oti6858_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; -} - /* module description and (de)initialization */ static int __init oti6858_init(void) -- 1.8.2.3