7 files changed, 75 insertions, 103 deletions

diff --git a/drivers/char/agp/parisc-agp.c b/drivers/char/agp/parisc-agp.c
index f4bb43fb8016..e077701ae3d9 100644
--- a/drivers/char/agp/parisc-agp.c
+++ b/drivers/char/agp/parisc-agp.c
@@ -225,7 +225,7 @@ static const struct agp_bridge_driver parisc_agp_driver = {
         .configure              = parisc_agp_configure,
         .fetch_size             = parisc_agp_fetch_size,
         .tlb_flush              = parisc_agp_tlbflush,
-        .mask_memory            = parisc_agp_mask_memory,
+        .mask_memory            = parisc_agp_page_mask_memory,
         .masks                  = parisc_agp_masks,
         .agp_enable             = parisc_agp_enable,
         .cache_flush            = global_cache_flush,
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index ff47907ff1bf..973be2f44195 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -1583,6 +1583,7 @@ static int n_tty_open(struct tty_struct *tty)
 
 static inline int input_available_p(struct tty_struct *tty, int amt)
 {
+        tty_flush_to_ldisc(tty);
         if (tty->icanon) {
                 if (tty->canon_data)
                         return 1;
diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index 6e6942c45f5b..d083c73d784a 100644
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -144,6 +144,8 @@ static int pty_write(struct tty_struct *tty, const unsigned char *buf,
 
 static int pty_write_room(struct tty_struct *tty)
 {
+        if (tty->stopped)
+                return 0;
         return pty_space(tty->link);
 }
 
diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index 0db35857e4d8..5d7a02f63e1c 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -35,7 +35,6 @@
 #include <linux/spinlock.h>
 #include <linux/vt_kern.h>
 #include <linux/workqueue.h>
-#include <linux/kexec.h>
 #include <linux/hrtimer.h>
 #include <linux/oom.h>
 
@@ -124,9 +123,12 @@ static struct sysrq_key_op sysrq_unraw_op = {
 static void sysrq_handle_crash(int key, struct tty_struct *tty)
 {
         char *killer = NULL;
+
+        panic_on_oops = 1;      /* force panic */
+        wmb();
         *killer = 1;
 }
-static struct sysrq_key_op sysrq_crashdump_op = {
+static struct sysrq_key_op sysrq_crash_op = {
         .handler        = sysrq_handle_crash,
         .help_msg       = "Crash",
         .action_msg     = "Trigger a crash",
@@ -401,7 +403,7 @@ static struct sysrq_key_op *sysrq_key_table[36] = {
          */
         NULL,                           /* a */
         &sysrq_reboot_op,               /* b */
-        &sysrq_crashdump_op,            /* c & ibm_emac driver debug */
+        &sysrq_crash_op,                /* c & ibm_emac driver debug */
         &sysrq_showlocks_op,            /* d */
         &sysrq_term_op,                 /* e */
         &sysrq_moom_op,                 /* f */
diff --git a/drivers/char/tty_buffer.c b/drivers/char/tty_buffer.c
index 810ee25d66a4..3108991c5c8b 100644
--- a/drivers/char/tty_buffer.c
+++ b/drivers/char/tty_buffer.c
@@ -462,6 +462,19 @@ static void flush_to_ldisc(struct work_struct *work)
 }
 
 /**
+ *      tty_flush_to_ldisc
+ *      @tty: tty to push
+ *
+ *      Push the terminal flip buffers to the line discipline.
+ *
+ *      Must not be called from IRQ context.
+ */
+void tty_flush_to_ldisc(struct tty_struct *tty)
+{
+        flush_to_ldisc(&tty->buf.work.work);
+}
+
+/**
  *      tty_flip_buffer_push    -       terminal
  *      @tty: tty to push
  *
diff --git a/drivers/char/tty_ldisc.c b/drivers/char/tty_ldisc.c
index acd76b767d4c..1733d3439ad2 100644
--- a/drivers/char/tty_ldisc.c
+++ b/drivers/char/tty_ldisc.c
@@ -48,6 +48,41 @@ static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
 /* Line disc dispatch table */
 static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
 
+static inline struct tty_ldisc *get_ldisc(struct tty_ldisc *ld)
+{
+        if (ld)
+                atomic_inc(&ld->users);
+        return ld;
+}
+
+static void put_ldisc(struct tty_ldisc *ld)
+{
+        unsigned long flags;
+
+        if (WARN_ON_ONCE(!ld))
+                return;
+
+        /*
+         * If this is the last user, free the ldisc, and
+         * release the ldisc ops.
+         *
+         * We really want an "atomic_dec_and_lock_irqsave()",
+         * but we don't have it, so this does it by hand.
+         */
+        local_irq_save(flags);
+        if (atomic_dec_and_lock(&ld->users, &tty_ldisc_lock)) {
+                struct tty_ldisc_ops *ldo = ld->ops;
+
+                ldo->refcount--;
+                module_put(ldo->owner);
+                spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+                kfree(ld);
+                return;
+        }
+        local_irq_restore(flags);
+}
+
 /**
  *      tty_register_ldisc      -       install a line discipline
  *      @disc: ldisc number
@@ -142,7 +177,7 @@ static struct tty_ldisc *tty_ldisc_try_get(int disc)
                         /* lock it */
                         ldops->refcount++;
                         ld->ops = ldops;
-                        ld->refcount = 0;
+                        atomic_set(&ld->users, 1);
                         err = 0;
                 }
         }
@@ -181,35 +216,6 @@ static struct tty_ldisc *tty_ldisc_get(int disc)
         return ld;
 }
 
-/**
- *      tty_ldisc_put           -       drop ldisc reference
- *      @ld: ldisc
- *
- *      Drop a reference to a line discipline. Manage refcounts and
- *      module usage counts. Free the ldisc once the recount hits zero.
- *
- *      Locking:
- *              takes tty_ldisc_lock to guard against ldisc races
- */
-
-static void tty_ldisc_put(struct tty_ldisc *ld)
-{
-        unsigned long flags;
-        int disc = ld->ops->num;
-        struct tty_ldisc_ops *ldo;
-
-        BUG_ON(disc < N_TTY || disc >= NR_LDISCS);
-
-        spin_lock_irqsave(&tty_ldisc_lock, flags);
-        ldo = tty_ldiscs[disc];
-        BUG_ON(ldo->refcount == 0);
-        ldo->refcount--;
-        module_put(ldo->owner);
-        spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-        WARN_ON(ld->refcount);
-        kfree(ld);
-}
-
 static void *tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
 {
         return (*pos < NR_LDISCS) ? pos : NULL;
@@ -234,7 +240,7 @@ static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
         if (IS_ERR(ld))
                 return 0;
         seq_printf(m, "%-10s %2d\n", ld->ops->name ? ld->ops->name : "???", i);
-        tty_ldisc_put(ld);
+        put_ldisc(ld);
         return 0;
 }
 
@@ -288,20 +294,17 @@ static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
  *      Locking: takes tty_ldisc_lock
  */
 
-static int tty_ldisc_try(struct tty_struct *tty)
+static struct tty_ldisc *tty_ldisc_try(struct tty_struct *tty)
 {
         unsigned long flags;
         struct tty_ldisc *ld;
-        int ret = 0;
 
         spin_lock_irqsave(&tty_ldisc_lock, flags);
-        ld = tty->ldisc;
-        if (test_bit(TTY_LDISC, &tty->flags)) {
-                ld->refcount++;
-                ret = 1;
-        }
+        ld = NULL;
+        if (test_bit(TTY_LDISC, &tty->flags))
+                ld = get_ldisc(tty->ldisc);
         spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-        return ret;
+        return ld;
 }
 
 /**
@@ -322,10 +325,11 @@ static int tty_ldisc_try(struct tty_struct *tty)
 
 struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
 {
+        struct tty_ldisc *ld;
+
         /* wait_event is a macro */
-        wait_event(tty_ldisc_wait, tty_ldisc_try(tty));
-        WARN_ON(tty->ldisc->refcount == 0);
-        return tty->ldisc;
+        wait_event(tty_ldisc_wait, (ld = tty_ldisc_try(tty)) != NULL);
+        return ld;
 }
 EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
 
@@ -342,9 +346,7 @@ EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
 
 struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
 {
-        if (tty_ldisc_try(tty))
-                return tty->ldisc;
-        return NULL;
+        return tty_ldisc_try(tty);
 }
 EXPORT_SYMBOL_GPL(tty_ldisc_ref);
 
@@ -360,21 +362,15 @@ EXPORT_SYMBOL_GPL(tty_ldisc_ref);
 
 void tty_ldisc_deref(struct tty_ldisc *ld)
 {
-        unsigned long flags;
-
-        BUG_ON(ld == NULL);
-
-        spin_lock_irqsave(&tty_ldisc_lock, flags);
-        if (ld->refcount == 0)
-                printk(KERN_ERR "tty_ldisc_deref: no references.\n");
-        else
-                ld->refcount--;
-        if (ld->refcount == 0)
-                wake_up(&tty_ldisc_wait);
-        spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+        put_ldisc(ld);
 }
 EXPORT_SYMBOL_GPL(tty_ldisc_deref);
 
+static inline void tty_ldisc_put(struct tty_ldisc *ld)
+{
+        put_ldisc(ld);
+}
+
 /**
  *      tty_ldisc_enable        -       allow ldisc use
  *      @tty: terminal to activate ldisc on
@@ -523,31 +519,6 @@ static int tty_ldisc_halt(struct tty_struct *tty)
 }
 
 /**
- *      tty_ldisc_wait_idle     -       wait for the ldisc to become idle
- *      @tty: tty to wait for
- *
- *      Wait for the line discipline to become idle. The discipline must
- *      have been halted for this to guarantee it remains idle.
- *
- *      tty_ldisc_lock protects the ref counts currently.
- */
-
-static int tty_ldisc_wait_idle(struct tty_struct *tty)
-{
-        unsigned long flags;
-        spin_lock_irqsave(&tty_ldisc_lock, flags);
-        while (tty->ldisc->refcount) {
-                spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-                if (wait_event_timeout(tty_ldisc_wait,
-                                tty->ldisc->refcount == 0, 5 * HZ) == 0)
-                        return -EBUSY;
-                spin_lock_irqsave(&tty_ldisc_lock, flags);
-        }
-        spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-        return 0;
-}
-
-/**
  *      tty_set_ldisc           -       set line discipline
  *      @tty: the terminal to set
  *      @ldisc: the line discipline
@@ -642,14 +613,6 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 
         flush_scheduled_work();
 
-        /* Let any existing reference holders finish */
-        retval = tty_ldisc_wait_idle(tty);
-        if (retval < 0) {
-                clear_bit(TTY_LDISC_CHANGING, &tty->flags);
-                tty_ldisc_put(new_ldisc);
-                return retval;
-        }
-
         mutex_lock(&tty->ldisc_mutex);
         if (test_bit(TTY_HUPPED, &tty->flags)) {
                 /* We were raced by the hangup method. It will have stomped
@@ -795,7 +758,6 @@ void tty_ldisc_hangup(struct tty_struct *tty)
                 if (tty->ldisc) {       /* Not yet closed */
                         /* Switch back to N_TTY */
                         tty_ldisc_halt(tty);
-                        tty_ldisc_wait_idle(tty);
                         tty_ldisc_reinit(tty);
                         /* At this point we have a closed ldisc and we want to
                            reopen it. We could defer this to the next open but
@@ -860,14 +822,6 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
         tty_ldisc_halt(tty);
         flush_scheduled_work();
 
-        /*
-         * Wait for any short term users (we know they are just driver
-         * side waiters as the file is closing so user count on the file
-         * side is zero.
-         */
-
-        tty_ldisc_wait_idle(tty);
-
         mutex_lock(&tty->ldisc_mutex);
         /*
          * Now kill off the ldisc
diff --git a/drivers/char/vr41xx_giu.c b/drivers/char/vr41xx_giu.c
deleted file mode 100644
index e69de29bb2d1..000000000000
--- a/drivers/char/vr41xx_giu.c
+++ /dev/null