1 files changed, 27 insertions, 31 deletions

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 742a5bc44be8..2a70563bbee1 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -26,6 +26,7 @@
 #include <linux/tty_flip.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/seq_file.h>
 #include <linux/spinlock.h>
 #include <linux/mutex.h>
 #include <linux/list.h>
@@ -421,57 +422,52 @@ static int serial_break(struct tty_struct *tty, int break_state)
         return 0;
 }
 
-static int serial_read_proc(char *page, char **start, off_t off, int count,
-                                                        int *eof, void *data)
+static int serial_proc_show(struct seq_file *m, void *v)
 {
         struct usb_serial *serial;
-        int length = 0;
         int i;
-        off_t begin = 0;
         char tmp[40];
 
         dbg("%s", __func__);
-        length += sprintf(page, "usbserinfo:1.0 driver:2.0\n");
-        for (i = 0; i < SERIAL_TTY_MINORS && length < PAGE_SIZE; ++i) {
+        seq_puts(m, "usbserinfo:1.0 driver:2.0\n");
+        for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
                 serial = usb_serial_get_by_index(i);
                 if (serial == NULL)
                         continue;
 
-                length += sprintf(page+length, "%d:", i);
+                seq_printf(m, "%d:", i);
                 if (serial->type->driver.owner)
-                        length += sprintf(page+length, " module:%s",
+                        seq_printf(m, " module:%s",
                                 module_name(serial->type->driver.owner));
-                length += sprintf(page+length, " name:\"%s\"",
+                seq_printf(m, " name:\"%s\"",
                                 serial->type->description);
-                length += sprintf(page+length, " vendor:%04x product:%04x",
+                seq_printf(m, " vendor:%04x product:%04x",
                         le16_to_cpu(serial->dev->descriptor.idVendor),
                         le16_to_cpu(serial->dev->descriptor.idProduct));
-                length += sprintf(page+length, " num_ports:%d",
-                                                        serial->num_ports);
-                length += sprintf(page+length, " port:%d",
-                                                        i - serial->minor + 1);
+                seq_printf(m, " num_ports:%d", serial->num_ports);
+                seq_printf(m, " port:%d", i - serial->minor + 1);
                 usb_make_path(serial->dev, tmp, sizeof(tmp));
-                length += sprintf(page+length, " path:%s", tmp);
+                seq_printf(m, " path:%s", tmp);
 
-                length += sprintf(page+length, "\n");
-                if ((length + begin) > (off + count)) {
-                        usb_serial_put(serial);
-                        goto done;
-                }
-                if ((length + begin) < off) {
-                        begin += length;
-                        length = 0;
-                }
+                seq_putc(m, '\n');
                 usb_serial_put(serial);
         }
-        *eof = 1;
-done:
-        if (off >= (length + begin))
-                return 0;
-        *start = page + (off-begin);
-        return (count < begin+length-off) ? count : begin+length-off;
+        return 0;
 }
 
+static int serial_proc_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, serial_proc_show, NULL);
+}
+
+static const struct file_operations serial_proc_fops = {
+        .owner          = THIS_MODULE,
+        .open           = serial_proc_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
 static int serial_tiocmget(struct tty_struct *tty, struct file *file)
 {
         struct usb_serial_port *port = tty->driver_data;
@@ -1113,9 +1109,9 @@ static const struct tty_operations serial_ops = {
         .unthrottle =           serial_unthrottle,
         .break_ctl =            serial_break,
         .chars_in_buffer =      serial_chars_in_buffer,
-        .read_proc =            serial_read_proc,
         .tiocmget =             serial_tiocmget,
         .tiocmset =             serial_tiocmset,
+        .proc_fops =            &serial_proc_fops,
 };
 
 struct tty_driver *usb_serial_tty_driver;