Staging: dgnc: Use goto for error handling

This patch introduces goto statments for error handling
and in cases where a lock needs to be released.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr)

@candidates exists@
identifier f, label;
statement s;
position p1, p2, p3;
@@

  f@p1(...) {
  ...when any

    if@p2(...) {
    ...when any
      s

      return@p3 ...;
    }
  ...when any
  }

@good1 exists@
identifier candidates.f, candidates.label;
statement candidates.s;
position candidates.p1, candidates.p2;
@@

  f@p1(...) {
  ...when any

    if(...) {
    ...when any
      s
      return ...;
    }
    ...when any

    if@p2(...) {...}
  ...when any
 }

@depends on good1@
identifier candidates.f, candidates.label;
position candidates.p1, candidates.p3;
@@

   f@p1(...) {
   ...when any
*  return@p3 ...;
  }

Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/dgnc/dgnc_cls.c b/drivers/staging/dgnc/dgnc_cls.c
index 634d3ea..66397d6 100644 (file)
--- a/drivers/staging/dgnc/dgnc_cls.c
+++ b/drivers/staging/dgnc/dgnc_cls.c
@@ -988,22 +988,16 @@ static void cls_copy_data_from_queue_to_uart(struct channel_t *ch)
        spin_lock_irqsave(&ch->ch_lock, flags);
 
        /* No data to write to the UART */
-       if (ch->ch_w_tail == ch->ch_w_head) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return;
-       }
+       if (ch->ch_w_tail == ch->ch_w_head)
+               goto exit_unlock;
 
        /* If port is "stopped", don't send any data to the UART */
        if ((ch->ch_flags & CH_FORCED_STOP) ||
-                                (ch->ch_flags & CH_BREAK_SENDING)) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return;
-       }
+                                (ch->ch_flags & CH_BREAK_SENDING))
+               goto exit_unlock;
 
-       if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM))) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return;
-       }
+       if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
+               goto exit_unlock;
 
        n = 32;
 
@@ -1053,6 +1047,7 @@ static void cls_copy_data_from_queue_to_uart(struct channel_t *ch)
        if (len_written > 0)
                ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 
+exit_unlock:
        spin_unlock_irqrestore(&ch->ch_lock, flags);
 }
 

diff --git a/drivers/staging/dgnc/dgnc_driver.c b/drivers/staging/dgnc/dgnc_driver.c
index ec7c155..9ae9014 100644 (file)
--- a/drivers/staging/dgnc/dgnc_driver.c
+++ b/drivers/staging/dgnc/dgnc_driver.c
@@ -549,30 +549,19 @@ static int dgnc_found_board(struct pci_dev *pdev, int id)
 
        rc = dgnc_tty_register(brd);
        if (rc < 0) {
-               dgnc_tty_uninit(brd);
                pr_err(DRVSTR ": Can't register tty devices (%d)\n", rc);
-               brd->state = BOARD_FAILED;
-               brd->dpastatus = BD_NOFEP;
                goto failed;
        }
 
        rc = dgnc_finalize_board_init(brd);
        if (rc < 0) {
-               dgnc_tty_uninit(brd);
                pr_err(DRVSTR ": Can't finalize board init (%d)\n", rc);
-               brd->state = BOARD_FAILED;
-               brd->dpastatus = BD_NOFEP;
-
                goto failed;
        }
 
        rc = dgnc_tty_init(brd);
        if (rc < 0) {
-               dgnc_tty_uninit(brd);
                pr_err(DRVSTR ": Can't init tty devices (%d)\n", rc);
-               brd->state = BOARD_FAILED;
-               brd->dpastatus = BD_NOFEP;
-
                goto failed;
        }
 
@@ -606,6 +595,9 @@ static int dgnc_found_board(struct pci_dev *pdev, int id)
        return 0;
 
 failed:
+       dgnc_tty_uninit(brd);
+       brd->state = BOARD_FAILED;
+       brd->dpastatus = BD_NOFEP;
 
        return -ENXIO;
 

diff --git a/drivers/staging/dgnc/dgnc_neo.c b/drivers/staging/dgnc/dgnc_neo.c
index 12e61ca..41105be 100644 (file)
--- a/drivers/staging/dgnc/dgnc_neo.c
+++ b/drivers/staging/dgnc/dgnc_neo.c
@@ -1420,16 +1420,13 @@ static void neo_copy_data_from_queue_to_uart(struct channel_t *ch)
        spin_lock_irqsave(&ch->ch_lock, flags);
 
        /* No data to write to the UART */
-       if (ch->ch_w_tail == ch->ch_w_head) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return;
-       }
+       if (ch->ch_w_tail == ch->ch_w_head)
+               goto exit_unlock;
 
        /* If port is "stopped", don't send any data to the UART */
-       if ((ch->ch_flags & CH_FORCED_STOP) || (ch->ch_flags & CH_BREAK_SENDING)) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return;
-       }
+       if ((ch->ch_flags & CH_FORCED_STOP) ||
+                (ch->ch_flags & CH_BREAK_SENDING))
+               goto exit_unlock;
 
        /*
         * If FIFOs are disabled. Send data directly to txrx register
@@ -1470,27 +1467,23 @@ static void neo_copy_data_from_queue_to_uart(struct channel_t *ch)
                        ch->ch_w_tail &= WQUEUEMASK;
                        ch->ch_txcount++;
                }
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return;
+
+               goto exit_unlock;
        }
 
        /*
         * We have to do it this way, because of the EXAR TXFIFO count bug.
         */
        if ((ch->ch_bd->dvid & 0xf0) < UART_XR17E158_DVID) {
-               if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM))) {
-                       spin_unlock_irqrestore(&ch->ch_lock, flags);
-                       return;
-               }
+               if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
+                       goto exit_unlock;
 
                len_written = 0;
 
                n = readb(&ch->ch_neo_uart->tfifo);
 
-               if ((unsigned int) n > ch->ch_t_tlevel) {
-                       spin_unlock_irqrestore(&ch->ch_lock, flags);
-                       return;
-               }
+               if ((unsigned int) n > ch->ch_t_tlevel)
+                       goto exit_unlock;
 
                n = UART_17158_TX_FIFOSIZE - ch->ch_t_tlevel;
        } else {
@@ -1554,6 +1547,7 @@ static void neo_copy_data_from_queue_to_uart(struct channel_t *ch)
                ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
        }
 
+exit_unlock:
        spin_unlock_irqrestore(&ch->ch_lock, flags);
 }