USB: ti_usb: use kfifo to implement write buffering (074ef65a) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/usb/serial/ti_usb_3410_5052.c

+14 −165

Original line number	Diff line number	Diff line
		@@ -30,7 +30,7 @@
		#include <linux/spinlock.h>
		#include <linux/ioctl.h>
		#include <linux/serial.h>
		#include <linux/circ_buf.h>
		#include <linux/kfifo.h>
		#include <linux/mutex.h>
		#include <linux/uaccess.h>
		#include <linux/usb.h>
		@@ -40,7 +40,7 @@

		/* Defines */

		#define TI_DRIVER_VERSION "v0.9"
		#define TI_DRIVER_VERSION "v0.10"
		#define TI_DRIVER_AUTHOR "Al Borchers <alborchers@steinerpoint.com>"
		#define TI_DRIVER_DESC "TI USB 3410/5052 Serial Driver"

		@@ -82,7 +82,7 @@ struct ti_port {
		spinlock_t tp_lock;
		int tp_read_urb_state;
		int tp_write_urb_in_use;
		struct circ_buf *tp_write_buf;
		struct kfifo write_fifo;
		};

		struct ti_device {
		@@ -144,15 +144,6 @@ static int ti_write_byte(struct ti_device *tdev, unsigned long addr,

		static int ti_download_firmware(struct ti_device *tdev);

		/* circular buffer */
		static struct circ_buf *ti_buf_alloc(void);
		static void ti_buf_free(struct circ_buf *cb);
		static void ti_buf_clear(struct circ_buf *cb);
		static int ti_buf_data_avail(struct circ_buf *cb);
		static int ti_buf_space_avail(struct circ_buf *cb);
		static int ti_buf_put(struct circ_buf cb, const char buf, int count);
		static int ti_buf_get(struct circ_buf cb, char buf, int count);


		/* Data */

		@@ -450,8 +441,8 @@ static int ti_startup(struct usb_serial *serial)
		tport->tp_closing_wait = closing_wait;
		init_waitqueue_head(&tport->tp_msr_wait);
		init_waitqueue_head(&tport->tp_write_wait);
		tport->tp_write_buf = ti_buf_alloc();
		if (tport->tp_write_buf == NULL) {
		if (kfifo_alloc(&tport->write_fifo, TI_WRITE_BUF_SIZE,
		GFP_KERNEL)) {
		dev_err(&dev->dev, "%s - out of memory\n", __func__);
		kfree(tport);
		status = -ENOMEM;
		@@ -468,7 +459,7 @@ static int ti_startup(struct usb_serial *serial)
		free_tports:
		for (--i; i >= 0; --i) {
		tport = usb_get_serial_port_data(serial->port[i]);
		ti_buf_free(tport->tp_write_buf);
		kfifo_free(&tport->write_fifo);
		kfree(tport);
		usb_set_serial_port_data(serial->port[i], NULL);
		}
		@@ -490,7 +481,7 @@ static void ti_release(struct usb_serial *serial)
		for (i = 0; i < serial->num_ports; ++i) {
		tport = usb_get_serial_port_data(serial->port[i]);
		if (tport) {
		ti_buf_free(tport->tp_write_buf);
		kfifo_free(&tport->write_fifo);
		kfree(tport);
		}
		}
		@@ -701,7 +692,6 @@ static int ti_write(struct tty_struct tty, struct usb_serial_port port,
		const unsigned char *data, int count)
		{
		struct ti_port *tport = usb_get_serial_port_data(port);
		unsigned long flags;

		dbg("%s - port %d", __func__, port->number);

		@@ -713,10 +703,8 @@ static int ti_write(struct tty_struct tty, struct usb_serial_port port,
		if (tport == NULL \|\| !tport->tp_is_open)
		return -ENODEV;

		spin_lock_irqsave(&tport->tp_lock, flags);
		count = ti_buf_put(tport->tp_write_buf, data, count);
		spin_unlock_irqrestore(&tport->tp_lock, flags);

		count = kfifo_in_locked(&tport->write_fifo, data, count,
		&tport->tp_lock);
		ti_send(tport);

		return count;
		@@ -736,7 +724,7 @@ static int ti_write_room(struct tty_struct *tty)
		return 0;

		spin_lock_irqsave(&tport->tp_lock, flags);
		room = ti_buf_space_avail(tport->tp_write_buf);
		room = kfifo_avail(&tport->write_fifo);
		spin_unlock_irqrestore(&tport->tp_lock, flags);

		dbg("%s - returns %d", __func__, room);
		@@ -757,7 +745,7 @@ static int ti_chars_in_buffer(struct tty_struct *tty)
		return 0;

		spin_lock_irqsave(&tport->tp_lock, flags);
		chars = ti_buf_data_avail(tport->tp_write_buf);
		chars = kfifo_len(&tport->write_fifo);
		spin_unlock_irqrestore(&tport->tp_lock, flags);

		dbg("%s - returns %d", __func__, chars);
		@@ -1309,7 +1297,7 @@ static void ti_send(struct ti_port *tport)
		if (tport->tp_write_urb_in_use)
		goto unlock;

		count = ti_buf_get(tport->tp_write_buf,
		count = kfifo_out(&tport->write_fifo,
		port->write_urb->transfer_buffer,
		port->bulk_out_size);

		@@ -1504,7 +1492,7 @@ static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
		add_wait_queue(&tport->tp_write_wait, &wait);
		for (;;) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (ti_buf_data_avail(tport->tp_write_buf) == 0
		if (kfifo_len(&tport->write_fifo) == 0
		\|\| timeout == 0 \|\| signal_pending(current)
		\|\| tdev->td_urb_error
		\|\| port->serial->disconnected) /* disconnect */
		@@ -1518,7 +1506,7 @@ static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)

		/* flush any remaining data in the buffer */
		if (flush)
		ti_buf_clear(tport->tp_write_buf);
		kfifo_reset_out(&tport->write_fifo);

		spin_unlock_irq(&tport->tp_lock);

		@@ -1761,142 +1749,3 @@ static int ti_download_firmware(struct ti_device *tdev)

		return 0;
		}


		/* Circular Buffer Functions */

		/*
		* ti_buf_alloc
		*
		* Allocate a circular buffer and all associated memory.
		*/

		static struct circ_buf *ti_buf_alloc(void)
		{
		struct circ_buf *cb;

		cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
		if (cb == NULL)
		return NULL;

		cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
		if (cb->buf == NULL) {
		kfree(cb);
		return NULL;
		}

		ti_buf_clear(cb);

		return cb;
		}


		/*
		* ti_buf_free
		*
		* Free the buffer and all associated memory.
		*/

		static void ti_buf_free(struct circ_buf *cb)
		{
		kfree(cb->buf);
		kfree(cb);
		}


		/*
		* ti_buf_clear
		*
		* Clear out all data in the circular buffer.
		*/

		static void ti_buf_clear(struct circ_buf *cb)
		{
		cb->head = cb->tail = 0;
		}


		/*
		* ti_buf_data_avail
		*
		* Return the number of bytes of data available in the circular
		* buffer.
		*/

		static int ti_buf_data_avail(struct circ_buf *cb)
		{
		return CIRC_CNT(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
		}


		/*
		* ti_buf_space_avail
		*
		* Return the number of bytes of space available in the circular
		* buffer.
		*/

		static int ti_buf_space_avail(struct circ_buf *cb)
		{
		return CIRC_SPACE(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
		}


		/*
		* ti_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 int ti_buf_put(struct circ_buf cb, const char buf, int count)
		{
		int c, ret = 0;

		while (1) {
		c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
		if (count < c)
		c = count;
		if (c <= 0)
		break;
		memcpy(cb->buf + cb->head, buf, c);
		cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
		buf += c;
		count -= c;
		ret += c;
		}

		return ret;
		}


		/*
		* ti_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 int ti_buf_get(struct circ_buf cb, char buf, int count)
		{
		int c, ret = 0;

		while (1) {
		c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
		if (count < c)
		c = count;
		if (c <= 0)
		break;
		memcpy(buf, cb->buf + cb->tail, c);
		cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
		buf += c;
		count -= c;
		ret += c;
		}

		return ret;
		}