Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6

* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (36 commits)
  serial: apbuart: Fixup apbuart_console_init()
  TTY: Add tty ioctl to figure device node of the system console.
  tty: add 'active' sysfs attribute to tty0 and console device
  drivers: serial: apbuart: Handle OF failures gracefully
  Serial: Avoid unbalanced IRQ wake disable during resume
  tty: fix typos/errors in tty_driver.h comments
  pch_uart : fix warnings for 64bit compile
  8250: fix uninitialized FIFOs
  ip2: fix compiler warning on ip2main_pci_tbl
  specialix: fix compiler warning on specialix_pci_tbl
  rocket: fix compiler warning on rocket_pci_ids
  8250: add a UPIO_DWAPB32 for 32 bit accesses
  8250: use container_of() instead of casting
  serial: omap-serial: Add support for kernel debugger
  serial: fix pch_uart kconfig & build
  drivers: char: hvc: add arm JTAG DCC console support
  RS485 documentation: add 16C950 UART description
  serial: ifx6x60: fix memory leak
  serial: ifx6x60: free IRQ on error
  Serial: EG20T: add PCH_UART driver
  ...

Fixed up conflicts in drivers/serial/apbuart.c with evil merge that
makes the code look fairly sane (unlike either side).

3 files changed, 197 insertions, 91 deletions

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index c5f8e5bda2b2..44b8412a04e8 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -19,7 +19,7 @@
  *
  * TO DO:
  *      Mostly done:    ioctls for setting modes/timing
- *      Partly done:    hooks so you can pull off frames to non tty devs
+ *      Partly done:    hooks so you can pull off frames to non tty devs
  *      Restart DLCI 0 when it closes ?
  *      Test basic encoding
  *      Improve the tx engine
@@ -73,8 +73,10 @@ module_param(debug, int, 0600);
 #define T2      (2 * HZ)
 #endif
 
-/* Semi-arbitary buffer size limits. 0710 is normally run with 32-64 byte
-   limits so this is plenty */
+/*
+ * Semi-arbitary buffer size limits. 0710 is normally run with 32-64 byte
+ * limits so this is plenty
+ */
 #define MAX_MRU 512
 #define MAX_MTU 512
 
@@ -184,6 +186,9 @@ struct gsm_mux {
 #define GSM_DATA                5
 #define GSM_FCS                 6
 #define GSM_OVERRUN             7
+#define GSM_LEN0                8
+#define GSM_LEN1                9
+#define GSM_SSOF                10
         unsigned int len;
         unsigned int address;
         unsigned int count;
@@ -191,6 +196,7 @@ struct gsm_mux {
         int encoding;
         u8 control;
         u8 fcs;
+        u8 received_fcs;
         u8 *txframe;                    /* TX framing buffer */
 
         /* Methods for the receiver side */
@@ -286,7 +292,7 @@ static spinlock_t gsm_mux_lock;
 #define MDM_DV                  0x40
 
 #define GSM0_SOF                0xF9
-#define GSM1_SOF                0x7E
+#define GSM1_SOF                0x7E
 #define GSM1_ESCAPE             0x7D
 #define GSM1_ESCAPE_BITS        0x20
 #define XON                     0x11
@@ -429,61 +435,63 @@ static void gsm_print_packet(const char *hdr, int addr, int cr,
         if (!(debug & 1))
                 return;
 
-        printk(KERN_INFO "%s %d) %c: ", hdr, addr, "RC"[cr]);
+        pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]);
 
         switch (control & ~PF) {
         case SABM:
-                printk(KERN_CONT "SABM");
+                pr_cont("SABM");
                 break;
         case UA:
-                printk(KERN_CONT "UA");
+                pr_cont("UA");
                 break;
         case DISC:
-                printk(KERN_CONT "DISC");
+                pr_cont("DISC");
                 break;
         case DM:
-                printk(KERN_CONT "DM");
+                pr_cont("DM");
                 break;
         case UI:
-                printk(KERN_CONT "UI");
+                pr_cont("UI");
                 break;
         case UIH:
-                printk(KERN_CONT "UIH");
+                pr_cont("UIH");
                 break;
         default:
                 if (!(control & 0x01)) {
-                        printk(KERN_CONT "I N(S)%d N(R)%d",
-                                (control & 0x0E) >> 1, (control & 0xE)>> 5);
+                        pr_cont("I N(S)%d N(R)%d",
+                                (control & 0x0E) >> 1, (control & 0xE) >> 5);
                 } else switch (control & 0x0F) {
-                case RR:
-                        printk("RR(%d)", (control & 0xE0) >> 5);
-                        break;
-                case RNR:
-                        printk("RNR(%d)", (control & 0xE0) >> 5);
-                        break;
-                case REJ:
-                        printk("REJ(%d)", (control & 0xE0) >> 5);
-                        break;
-                default:
-                        printk(KERN_CONT "[%02X]", control);
+                        case RR:
+                                pr_cont("RR(%d)", (control & 0xE0) >> 5);
+                                break;
+                        case RNR:
+                                pr_cont("RNR(%d)", (control & 0xE0) >> 5);
+                                break;
+                        case REJ:
+                                pr_cont("REJ(%d)", (control & 0xE0) >> 5);
+                                break;
+                        default:
+                                pr_cont("[%02X]", control);
                 }
         }
 
         if (control & PF)
-                printk(KERN_CONT "(P)");
+                pr_cont("(P)");
         else
-                printk(KERN_CONT "(F)");
+                pr_cont("(F)");
 
         if (dlen) {
                 int ct = 0;
                 while (dlen--) {
-                        if (ct % 8 == 0)
-                                printk(KERN_CONT "\n    ");
-                        printk(KERN_CONT "%02X ", *data++);
+                        if (ct % 8 == 0) {
+                                pr_cont("\n");
+                                pr_debug("    ");
+                        }
+                        pr_cont("%02X ", *data++);
                         ct++;
                 }
         }
-        printk(KERN_CONT "\n");
+        pr_cont("\n");
 }
 
 
@@ -522,11 +530,13 @@ static void hex_packet(const unsigned char *p, int len)
 {
         int i;
         for (i = 0; i < len; i++) {
-                if (i && (i % 16) == 0)
-                        printk("\n");
-                printk("%02X ", *p++);
+                if (i && (i % 16) == 0) {
+                        pr_cont("\n");
+                        pr_debug("");
+                }
+                pr_cont("%02X ", *p++);
         }
-        printk("\n");
+        pr_cont("\n");
 }
 
 /**
@@ -676,7 +686,7 @@ static void gsm_data_kick(struct gsm_mux *gsm)
                 }
 
                 if (debug & 4) {
-                        printk("gsm_data_kick: \n");
+                        pr_debug("gsm_data_kick:\n");
                         hex_packet(gsm->txframe, len);
                 }
 
@@ -1231,7 +1241,7 @@ static void gsm_control_response(struct gsm_mux *gsm, unsigned int command,
 }
 
 /**
- *      gsm_control_transmit    -       send control packet
+ *      gsm_control_transmit    -       send control packet
  *      @gsm: gsm mux
  *      @ctrl: frame to send
  *
@@ -1361,7 +1371,7 @@ static void gsm_dlci_close(struct gsm_dlci *dlci)
 {
         del_timer(&dlci->t1);
         if (debug & 8)
-                printk("DLCI %d goes closed.\n", dlci->addr);
+                pr_debug("DLCI %d goes closed.\n", dlci->addr);
         dlci->state = DLCI_CLOSED;
         if (dlci->addr != 0) {
                 struct tty_struct  *tty = tty_port_tty_get(&dlci->port);
@@ -1392,7 +1402,7 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
         /* This will let a tty open continue */
         dlci->state = DLCI_OPEN;
         if (debug & 8)
-                printk("DLCI %d goes open.\n", dlci->addr);
+                pr_debug("DLCI %d goes open.\n", dlci->addr);
         wake_up(&dlci->gsm->event);
 }
 
@@ -1494,29 +1504,29 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len)
         unsigned int modem = 0;
 
         if (debug & 16)
-                printk("%d bytes for tty %p\n", len, tty);
+                pr_debug("%d bytes for tty %p\n", len, tty);
         if (tty) {
                 switch (dlci->adaption)  {
-                        /* Unsupported types */
-                        /* Packetised interruptible data */
-                        case 4:
-                                break;
-                        /* Packetised uininterruptible voice/data */
-                        case 3:
-                                break;
-                        /* Asynchronous serial with line state in each frame */
-                        case 2:
-                                while (gsm_read_ea(&modem, *data++) == 0) {
-                                        len--;
-                                        if (len == 0)
-                                                return;
-                                }
-                                gsm_process_modem(tty, dlci, modem);
-                        /* Line state will go via DLCI 0 controls only */
-                        case 1:
-                        default:
-                                tty_insert_flip_string(tty, data, len);
-                                tty_flip_buffer_push(tty);
+                /* Unsupported types */
+                /* Packetised interruptible data */
+                case 4:
+                        break;
+                /* Packetised uininterruptible voice/data */
+                case 3:
+                        break;
+                /* Asynchronous serial with line state in each frame */
+                case 2:
+                        while (gsm_read_ea(&modem, *data++) == 0) {
+                                len--;
+                                if (len == 0)
+                                        return;
+                        }
+                        gsm_process_modem(tty, dlci, modem);
+                /* Line state will go via DLCI 0 controls only */
+                case 1:
+                default:
+                        tty_insert_flip_string(tty, data, len);
+                        tty_flip_buffer_push(tty);
                 }
                 tty_kref_put(tty);
         }
@@ -1625,7 +1635,6 @@ static void gsm_dlci_free(struct gsm_dlci *dlci)
         kfree(dlci);
 }
 
-
 /*
  *      LAPBish link layer logic
  */
@@ -1650,10 +1659,12 @@ static void gsm_queue(struct gsm_mux *gsm)
 
         if ((gsm->control & ~PF) == UI)
                 gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len);
+        /* generate final CRC with received FCS */
+        gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs);
         if (gsm->fcs != GOOD_FCS) {
                 gsm->bad_fcs++;
                 if (debug & 4)
-                        printk("BAD FCS %02x\n", gsm->fcs);
+                        pr_debug("BAD FCS %02x\n", gsm->fcs);
                 return;
         }
         address = gsm->address >> 1;
@@ -1748,6 +1759,8 @@ invalid:
 
 static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
 {
+        unsigned int len;
+
         switch (gsm->state) {
         case GSM_SEARCH:        /* SOF marker */
                 if (c == GSM0_SOF) {
@@ -1756,8 +1769,8 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
                         gsm->len = 0;
                         gsm->fcs = INIT_FCS;
                 }
-                break;          /* Address EA */
-        case GSM_ADDRESS:
+                break;
+        case GSM_ADDRESS:       /* Address EA */
                 gsm->fcs = gsm_fcs_add(gsm->fcs, c);
                 if (gsm_read_ea(&gsm->address, c))
                         gsm->state = GSM_CONTROL;
@@ -1765,9 +1778,9 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
         case GSM_CONTROL:       /* Control Byte */
                 gsm->fcs = gsm_fcs_add(gsm->fcs, c);
                 gsm->control = c;
-                gsm->state = GSM_LEN;
+                gsm->state = GSM_LEN0;
                 break;
-        case GSM_LEN:           /* Length EA */
+        case GSM_LEN0:          /* Length EA */
                 gsm->fcs = gsm_fcs_add(gsm->fcs, c);
                 if (gsm_read_ea(&gsm->len, c)) {
                         if (gsm->len > gsm->mru) {
@@ -1776,8 +1789,28 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
                                 break;
                         }
                         gsm->count = 0;
-                        gsm->state = GSM_DATA;
+                        if (!gsm->len)
+                                gsm->state = GSM_FCS;
+                        else
+                                gsm->state = GSM_DATA;
+                        break;
+                }
+                gsm->state = GSM_LEN1;
+                break;
+        case GSM_LEN1:
+                gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+                len = c;
+                gsm->len |= len << 7;
+                if (gsm->len > gsm->mru) {
+                        gsm->bad_size++;
+                        gsm->state = GSM_SEARCH;
+                        break;
                 }
+                gsm->count = 0;
+                if (!gsm->len)
+                        gsm->state = GSM_FCS;
+                else
+                        gsm->state = GSM_DATA;
                 break;
         case GSM_DATA:          /* Data */
                 gsm->buf[gsm->count++] = c;
@@ -1785,16 +1818,25 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
                         gsm->state = GSM_FCS;
                 break;
         case GSM_FCS:           /* FCS follows the packet */
-                gsm->fcs = c;
+                gsm->received_fcs = c;
+                if (c == GSM0_SOF) {
+                        gsm->state = GSM_SEARCH;
+                        break;
+                }
                 gsm_queue(gsm);
-                /* And then back for the next frame */
-                gsm->state = GSM_SEARCH;
+                gsm->state = GSM_SSOF;
+                break;
+        case GSM_SSOF:
+                if (c == GSM0_SOF) {
+                        gsm->state = GSM_SEARCH;
+                        break;
+                }
                 break;
         }
 }
 
 /**
- *      gsm0_receive    -       perform processing for non-transparency
+ *      gsm1_receive    -       perform processing for non-transparency
  *      @gsm: gsm data for this ldisc instance
  *      @c: character
  *
@@ -1856,7 +1898,7 @@ static void gsm1_receive(struct gsm_mux *gsm, unsigned char c)
                 gsm->state = GSM_DATA;
                 break;
         case GSM_DATA:          /* Data */
-                if (gsm->count > gsm->mru ) {   /* Allow one for the FCS */
+                if (gsm->count > gsm->mru) {    /* Allow one for the FCS */
                         gsm->state = GSM_OVERRUN;
                         gsm->bad_size++;
                 } else
@@ -2034,9 +2076,6 @@ struct gsm_mux *gsm_alloc_mux(void)
 }
 EXPORT_SYMBOL_GPL(gsm_alloc_mux);
 
-
-
-
 /**
  *      gsmld_output            -       write to link
  *      @gsm: our mux
@@ -2054,7 +2093,7 @@ static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
                 return -ENOSPC;
         }
         if (debug & 4) {
-                printk("-->%d bytes out\n", len);
+                pr_debug("-->%d bytes out\n", len);
                 hex_packet(data, len);
         }
         gsm->tty->ops->write(gsm->tty, data, len);
@@ -2111,7 +2150,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
         char flags;
 
         if (debug & 4) {
-                printk("Inbytes %dd\n", count);
+                pr_debug("Inbytes %dd\n", count);
                 hex_packet(cp, count);
         }
 
@@ -2128,7 +2167,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
                         gsm->error(gsm, *dp, flags);
                         break;
                 default:
-                        printk(KERN_ERR "%s: unknown flag %d\n",
+                        WARN_ONCE("%s: unknown flag %d\n",
                                tty_name(tty, buf), flags);
                         break;
                 }
@@ -2323,7 +2362,7 @@ static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm,
         int need_restart = 0;
 
         /* Stuff we don't support yet - UI or I frame transport, windowing */
-        if ((c->adaption !=1 && c->adaption != 2) || c->k)
+        if ((c->adaption != 1 && c->adaption != 2) || c->k)
                 return -EOPNOTSUPP;
         /* Check the MRU/MTU range looks sane */
         if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8)
@@ -2418,7 +2457,7 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
                         c.i = 1;
                 else
                         c.i = 2;
-                printk("Ftype %d i %d\n", gsm->ftype, c.i);
+                pr_debug("Ftype %d i %d\n", gsm->ftype, c.i);
                 c.mru = gsm->mru;
                 c.mtu = gsm->mtu;
                 c.k = 0;
@@ -2712,14 +2751,15 @@ static int __init gsm_init(void)
         /* Fill in our line protocol discipline, and register it */
         int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet);
         if (status != 0) {
-                printk(KERN_ERR "n_gsm: can't register line discipline (err = %d)\n", status);
+                pr_err("n_gsm: can't register line discipline (err = %d)\n",
+                                                                status);
                 return status;
         }
 
         gsm_tty_driver = alloc_tty_driver(256);
         if (!gsm_tty_driver) {
                 tty_unregister_ldisc(N_GSM0710);
-                printk(KERN_ERR "gsm_init: tty allocation failed.\n");
+                pr_err("gsm_init: tty allocation failed.\n");
                 return -EINVAL;
         }
         gsm_tty_driver->owner   = THIS_MODULE;
@@ -2730,7 +2770,7 @@ static int __init gsm_init(void)
         gsm_tty_driver->type            = TTY_DRIVER_TYPE_SERIAL;
         gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL;
         gsm_tty_driver->flags   = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV
-                                                        | TTY_DRIVER_HARDWARE_BREAK;
+                                                | TTY_DRIVER_HARDWARE_BREAK;
         gsm_tty_driver->init_termios    = tty_std_termios;
         /* Fixme */
         gsm_tty_driver->init_termios.c_lflag &= ~ECHO;
@@ -2741,10 +2781,11 @@ static int __init gsm_init(void)
         if (tty_register_driver(gsm_tty_driver)) {
                 put_tty_driver(gsm_tty_driver);
                 tty_unregister_ldisc(N_GSM0710);
-                printk(KERN_ERR "gsm_init: tty registration failed.\n");
+                pr_err("gsm_init: tty registration failed.\n");
                 return -EBUSY;
         }
-        printk(KERN_INFO "gsm_init: loaded as %d,%d.\n", gsm_tty_driver->major, gsm_tty_driver->minor_start);
+        pr_debug("gsm_init: loaded as %d,%d.\n",
+                        gsm_tty_driver->major, gsm_tty_driver->minor_start);
         return 0;
 }
 
@@ -2752,10 +2793,10 @@ static void __exit gsm_exit(void)
 {
         int status = tty_unregister_ldisc(N_GSM0710);
         if (status != 0)
-                printk(KERN_ERR "n_gsm: can't unregister line discipline (err = %d)\n", status);
+                pr_err("n_gsm: can't unregister line discipline (err = %d)\n",
+                                                                status);
         tty_unregister_driver(gsm_tty_driver);
         put_tty_driver(gsm_tty_driver);
-        printk(KERN_INFO "gsm_init: unloaded.\n");
 }
 
 module_init(gsm_init);
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 35480dd57a30..464d09d97873 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2627,6 +2627,11 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                 return put_user(tty->ldisc->ops->num, (int __user *)p);
         case TIOCSETD:
                 return tiocsetd(tty, p);
+        case TIOCGDEV:
+        {
+                unsigned int ret = new_encode_dev(tty_devnum(real_tty));
+                return put_user(ret, (unsigned int __user *)p);
+        }
         /*
          * Break handling
          */
@@ -3241,9 +3246,45 @@ static int __init tty_class_init(void)
 postcore_initcall(tty_class_init);
 
 /* 3/2004 jmc: why do these devices exist? */
-
 static struct cdev tty_cdev, console_cdev;
 
+static ssize_t show_cons_active(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        struct console *cs[16];
+        int i = 0;
+        struct console *c;
+        ssize_t count = 0;
+
+        acquire_console_sem();
+        for (c = console_drivers; c; c = c->next) {
+                if (!c->device)
+                        continue;
+                if (!c->write)
+                        continue;
+                if ((c->flags & CON_ENABLED) == 0)
+                        continue;
+                cs[i++] = c;
+                if (i >= ARRAY_SIZE(cs))
+                        break;
+        }
+        while (i--)
+                count += sprintf(buf + count, "%s%d%c",
+                                 cs[i]->name, cs[i]->index, i ? ' ':'\n');
+        release_console_sem();
+
+        return count;
+}
+static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL);
+
+static struct device *consdev;
+
+void console_sysfs_notify(void)
+{
+        if (consdev)
+                sysfs_notify(&consdev->kobj, NULL, "active");
+}
+
 /*
  * Ok, now we can initialize the rest of the tty devices and can count
  * on memory allocations, interrupts etc..
@@ -3254,15 +3295,18 @@ int __init tty_init(void)
         if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
             register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
                 panic("Couldn't register /dev/tty driver\n");
-        device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
-                              "tty");
+        device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
 
         cdev_init(&console_cdev, &console_fops);
         if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
             register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
                 panic("Couldn't register /dev/console driver\n");
-        device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
+        consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
                               "console");
+        if (IS_ERR(consdev))
+                consdev = NULL;
+        else
+                device_create_file(consdev, &dev_attr_active);
 
 #ifdef CONFIG_VT
         vty_init(&console_fops);
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index a8ec48ed14d9..76407eca9ab0 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -236,6 +236,14 @@ enum {
 };
 
 /*
+ * /sys/class/tty/tty0/
+ *
+ * the attribute 'active' contains the name of the current vc
+ * console and it supports poll() to detect vc switches
+ */
+static struct device *tty0dev;
+
+/*
  * Notifier list for console events.
  */
 static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
@@ -688,6 +696,8 @@ void redraw_screen(struct vc_data *vc, int is_switch)
                         save_screen(old_vc);
                         set_origin(old_vc);
                 }
+                if (tty0dev)
+                        sysfs_notify(&tty0dev->kobj, NULL, "active");
         } else {
                 hide_cursor(vc);
                 redraw = 1;
@@ -2967,13 +2977,24 @@ static const struct tty_operations con_ops = {
 
 static struct cdev vc0_cdev;
 
+static ssize_t show_tty_active(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        return sprintf(buf, "tty%d\n", fg_console + 1);
+}
+static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
+
 int __init vty_init(const struct file_operations *console_fops)
 {
         cdev_init(&vc0_cdev, console_fops);
         if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
             register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
                 panic("Couldn't register /dev/tty0 driver\n");
-        device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+        tty0dev = device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+        if (IS_ERR(tty0dev))
+                tty0dev = NULL;
+        else
+                device_create_file(tty0dev, &dev_attr_active);
 
         vcs_init();