[ALSA] HDA/ALC260: 4/7 - add GPIO switches to test model

[linux-2.6-omap-h63xx.git] / drivers / char / tty_io.c

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 1eda82b31a61e8d890d551ead0488fdb675993eb..53d3d066554e556b4110398990294a12af9d1c97 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -253,6 +253,7 @@ static void tty_buffer_free_all(struct tty_struct *tty)
 
 static void tty_buffer_init(struct tty_struct *tty)
 {
+       spin_lock_init(&tty->buf.lock);
        tty->buf.head = NULL;
        tty->buf.tail = NULL;
        tty->buf.free = NULL;
@@ -266,6 +267,9 @@ static struct tty_buffer *tty_buffer_alloc(size_t size)
        p->used = 0;
        p->size = size;
        p->next = NULL;
+       p->active = 0;
+       p->commit = 0;
+       p->read = 0;
        p->char_buf_ptr = (char *)(p->data);
        p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size;
 /*     printk("Flip create %p\n", p); */
@@ -296,8 +300,10 @@ static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
                        *tbh = t->next;
                        t->next = NULL;
                        t->used = 0;
+                       t->commit = 0;
+                       t->read = 0;
                        /* DEBUG ONLY */
-                       memset(t->data, '*', size);
+/*                     memset(t->data, '*', size); */
 /*                     printk("Flip recycle %p\n", t); */
                        return t;
                }
@@ -312,26 +318,37 @@ static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
 
 int tty_buffer_request_room(struct tty_struct *tty, size_t size)
 {
-       struct tty_buffer *b = tty->buf.head, *n;
-       int left = 0;
+       struct tty_buffer *b, *n;
+       int left;
+       unsigned long flags;
+
+       spin_lock_irqsave(&tty->buf.lock, flags);
 
        /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
           remove this conditional if its worth it. This would be invisible
           to the callers */
-       if(b != NULL)
+       if ((b = tty->buf.tail) != NULL) {
                left = b->size - b->used;
-       if(left >= size)
-               return size;
-       /* This is the slow path - looking for new buffers to use */
-       n = tty_buffer_find(tty, size);
-       if(n == NULL)
-               return left;
-       n->next = b;
-       if(b != NULL)
-               b->next = n;
-       else
-               tty->buf.head = n;
-       tty->buf.tail = n;
+               b->active = 1;
+       } else
+               left = 0;
+
+       if (left < size) {
+               /* This is the slow path - looking for new buffers to use */
+               if ((n = tty_buffer_find(tty, size)) != NULL) {
+                       if (b != NULL) {
+                               b->next = n;
+                               b->active = 0;
+                               b->commit = b->used;
+                       } else
+                               tty->buf.head = n;
+                       tty->buf.tail = n;
+                       n->active = 1;
+               } else
+                       size = left;
+       }
+
+       spin_unlock_irqrestore(&tty->buf.lock, flags);
        return size;
 }
 
@@ -397,10 +414,12 @@ EXPORT_SYMBOL_GPL(tty_insert_flip_string_flags);
 int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size)
 {
        int space = tty_buffer_request_room(tty, size);
-       struct tty_buffer *tb = tty->buf.tail;
-       *chars = tb->char_buf_ptr + tb->used;
-       memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
-       tb->used += space;
+       if (likely(space)) {
+               struct tty_buffer *tb = tty->buf.tail;
+               *chars = tb->char_buf_ptr + tb->used;
+               memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
+               tb->used += space;
+       }
        return space;
 }
 
@@ -417,10 +436,12 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
 int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char **chars, char **flags, size_t size)
 {
        int space = tty_buffer_request_room(tty, size);
-       struct tty_buffer *tb = tty->buf.tail;
-       *chars = tb->char_buf_ptr + tb->used;
-       *flags = tb->flag_buf_ptr + tb->used;
-       tb->used += space;
+       if (likely(space)) {
+               struct tty_buffer *tb = tty->buf.tail;
+               *chars = tb->char_buf_ptr + tb->used;
+               *flags = tb->flag_buf_ptr + tb->used;
+               tb->used += space;
+       }
        return space;
 }
 
@@ -1820,7 +1841,6 @@ static void release_dev(struct file * filp)
                tty_closing = tty->count <= 1;
                o_tty_closing = o_tty &&
                        (o_tty->count <= (pty_master ? 1 : 0));
-               up(&tty_sem);
                do_sleep = 0;
 
                if (tty_closing) {
@@ -1848,6 +1868,7 @@ static void release_dev(struct file * filp)
 
                printk(KERN_WARNING "release_dev: %s: read/write wait queue "
                                    "active!\n", tty_name(tty, buf));
+               up(&tty_sem);
                schedule();
        }       
 
@@ -1856,8 +1877,6 @@ static void release_dev(struct file * filp)
         * both sides, and we've completed the last operation that could 
         * block, so it's safe to proceed with closing.
         */
-        
-       down(&tty_sem);
        if (pty_master) {
                if (--o_tty->count < 0) {
                        printk(KERN_WARNING "release_dev: bad pty slave count "
@@ -1871,7 +1890,6 @@ static void release_dev(struct file * filp)
                       tty->count, tty_name(tty, buf));
                tty->count = 0;
        }
-       up(&tty_sem);
        
        /*
         * We've decremented tty->count, so we need to remove this file
@@ -1916,6 +1934,8 @@ static void release_dev(struct file * filp)
                read_unlock(&tasklist_lock);
        }
 
+       up(&tty_sem);
+
        /* check whether both sides are closing ... */
        if (!tty_closing || (o_tty && !o_tty_closing))
                return;
@@ -2736,6 +2756,9 @@ static void flush_to_ldisc(void *private_)
        unsigned long   flags;
        struct tty_ldisc *disc;
        struct tty_buffer *tbuf;
+       int count;
+       char *char_buf;
+       unsigned char *flag_buf;
 
        disc = tty_ldisc_ref(tty);
        if (disc == NULL)       /*  !TTY_LDISC */
@@ -2748,19 +2771,24 @@ static void flush_to_ldisc(void *private_)
                schedule_delayed_work(&tty->buf.work, 1);
                goto out;
        }
-       spin_lock_irqsave(&tty->read_lock, flags);
+       spin_lock_irqsave(&tty->buf.lock, flags);
        while((tbuf = tty->buf.head) != NULL) {
+               while ((count = tbuf->commit - tbuf->read) != 0) {
+                       char_buf = tbuf->char_buf_ptr + tbuf->read;
+                       flag_buf = tbuf->flag_buf_ptr + tbuf->read;
+                       tbuf->read += count;
+                       spin_unlock_irqrestore(&tty->buf.lock, flags);
+                       disc->receive_buf(tty, char_buf, flag_buf, count);
+                       spin_lock_irqsave(&tty->buf.lock, flags);
+               }
+               if (tbuf->active)
+                       break;
                tty->buf.head = tbuf->next;
-               spin_unlock_irqrestore(&tty->read_lock, flags);
-               /* printk("Process buffer %p for %d\n", tbuf, tbuf->used); */
-               disc->receive_buf(tty, tbuf->char_buf_ptr,
-                                      tbuf->flag_buf_ptr,
-                                      tbuf->used);
-               spin_lock_irqsave(&tty->read_lock, flags);
+               if (tty->buf.head == NULL)
+                       tty->buf.tail = NULL;
                tty_buffer_free(tty, tbuf);
        }
-       tty->buf.tail = NULL;
-       spin_unlock_irqrestore(&tty->read_lock, flags);
+       spin_unlock_irqrestore(&tty->buf.lock, flags);
 out:
        tty_ldisc_deref(disc);
 }
@@ -2852,6 +2880,14 @@ EXPORT_SYMBOL(tty_get_baud_rate);
 
 void tty_flip_buffer_push(struct tty_struct *tty)
 {
+       unsigned long flags;
+       spin_lock_irqsave(&tty->buf.lock, flags);
+       if (tty->buf.tail != NULL) {
+               tty->buf.tail->active = 0;
+               tty->buf.tail->commit = tty->buf.tail->used;
+       }
+       spin_unlock_irqrestore(&tty->buf.lock, flags);
+
        if (tty->low_latency)
                flush_to_ldisc((void *) tty);
        else