tty open failed

来源：互联网发布：linux socket 库编辑：程序博客网时间：2024/05/16 09:44

tty_open

-> if (tty) { retval = tty_reopen(tty);}

static int tty_reopen(struct tty_struct *tty)
{
   struct tty_driver *driver = tty->driver;

   if (test_bit(TTY_CLOSING, &tty->flags) ||
           test_bit(TTY_HUPPING, &tty->flags) ||
           test_bit(TTY_LDISC_CHANGING, &tty->flags))
       return -EIO;

   if (driver->type == TTY_DRIVER_TYPE_PTY &&
        driver->subtype == PTY_TYPE_MASTER) {
       /*
       * special case for PTY masters: only one open permitted,
       * and the slave side open count is incremented as well.
       */
       if (tty->count)
           return -EIO;

       tty->link->count++;
   }
   tty->count++;

   mutex_lock(&tty->ldisc_mutex);
   WARN_ON(!test_bit(TTY_LDISC, &tty->flags));
   mutex_unlock(&tty->ldisc_mutex);

   return 0;
}

/*---------------------------------------------------------------------------*/
static void smd_ch_irq_tasklet_handler(unsigned long data)
{
   unsigned char *ptr;
   int avail;
   struct tty_struct *tty;
   int index=data;
   unsigned long flags;
   struct smd_tty_info *tty_info = &driver_info->smd_tty[index];
   dbg("enter %s\n",__func__);
   spin_lock_irqsave(&driver_info->lock, flags);
   tty = tty_port_tty_get(&tty_info->port);
   if (!tty){
       spin_unlock_irqrestore(&driver_info->lock, flags);
       return;
   }
   avail = smd_stream_read_avail(tty_info->ch);
   if (!avail){
       spin_unlock_irqrestore(&driver_info->lock, flags);
       return;
   }
   avail = tty_prepare_flip_string(tty, &ptr, avail);
   if(!avail){
       spin_unlock_irqrestore(&driver_info->lock, flags);
       pr_err("smd_ch_irq_tasklet_handler: cannot get space from tty_buffer!\n");
       return;
   }
   smd_stream_read(tty_info->ch,ptr,avail);
   smd_send_intr(tty_info->a2b_int_rx);
   tty_flip_buffer_push(tty);
   tty_kref_put(tty);
   spin_unlock_irqrestore(&driver_info->lock, flags);
}

更改为：

/*---------------------------------------------------------------------------*/
static void smd_ch_irq_tasklet_handler(unsigned long data)
{
   unsigned char *ptr;
   int avail;
   struct tty_struct *tty;
   int index=data;
   unsigned long flags;
   struct smd_tty_info *tty_info = &driver_info->smd_tty[index];
   dbg("enter %s\n",__func__);
   spin_lock_irqsave(&driver_info->lock, flags);
   tty = tty_port_tty_get(&tty_info->port);
   if (!tty){
       spin_unlock_irqrestore(&driver_info->lock, flags);
       return;
   }
   avail = smd_stream_read_avail(tty_info->ch);
   if (!avail){
       tty_kref_put(tty);
       spin_unlock_irqrestore(&driver_info->lock, flags);
       return;
   }
   avail = tty_prepare_flip_string(tty, &ptr, avail);
   if(!avail){
       tty_kref_put(tty);
       spin_unlock_irqrestore(&driver_info->lock, flags);
       pr_err("smd_ch_irq_tasklet_handler: cannot get space from tty_buffer!\n");
       return;
   }
   smd_stream_read(tty_info->ch,ptr,avail);
   smd_send_intr(tty_info->a2b_int_rx);
   tty_flip_buffer_push(tty);
   tty_kref_put(tty);
   spin_unlock_irqrestore(&driver_info->lock, flags);
}

就是说tty_port_tty_get和tty_kref_put没有成对出现

具体的原因，有时间在填上。

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