[PATCH 3/3] Staging: dgnc: Use goto for spinlock release before return

[Quentin Lambert]

spin_unlock_irqrestore() is called at several
different places before exiting. This patch uses a goto statement
to factorize these calls.

Coccinelle was used to generate this patch.

Signed-off-by: Quentin Lambert <lambert.quen...@gmail.com>
---
 drivers/staging/dgnc/dgnc_tty.c | 48 ++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 25 deletions(-)

diff --git a/drivers/staging/dgnc/dgnc_tty.c b/drivers/staging/dgnc/dgnc_tty.c
index 8179342..2dcc51e 100644
--- a/drivers/staging/dgnc/dgnc_tty.c
+++ b/drivers/staging/dgnc/dgnc_tty.c
@@ -507,7 +507,7 @@ void dgnc_input(struct channel_t *ch)
 {
        struct dgnc_board *bd;
        struct tty_struct *tp;
-       struct tty_ldisc *ld;
+       struct tty_ldisc *ld = NULL;
        uint    rmask;
        ushort  head;
        ushort  tail;
@@ -539,10 +539,8 @@ void dgnc_input(struct channel_t *ch)
        tail = ch->ch_r_tail & rmask;
        data_len = (head - tail) & rmask;
 
-       if (data_len == 0) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return;
-       }
+       if (data_len == 0)
+               goto exit_unlock;
 
        /*
         * If the device is not open, or CREAD is off,
@@ -556,17 +554,14 @@ void dgnc_input(struct channel_t *ch)
                /* Force queue flow control to be released, if needed */
                dgnc_check_queue_flow_control(ch);
 
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return;
+               goto exit_unlock;
        }
 
        /*
         * If we are throttled, simply don't read any data.
         */
-       if (ch->ch_flags & CH_FORCED_STOPI) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return;
-       }
+       if (ch->ch_flags & CH_FORCED_STOPI)
+               goto exit_unlock;
 
        flip_len = TTY_FLIPBUF_SIZE;
 
@@ -604,12 +599,8 @@ void dgnc_input(struct channel_t *ch)
                }
        }
 
-       if (len <= 0) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               if (ld)
-                       tty_ldisc_deref(ld);
-               return;
-       }
+       if (len <= 0)
+               goto exit_unlock;
 
        /*
         * The tty layer in the kernel has changed in 2.6.16+.
@@ -677,6 +668,12 @@ void dgnc_input(struct channel_t *ch)
 
        if (ld)
                tty_ldisc_deref(ld);
+       return;
+
+exit_unlock:
+       if (ld)
+               tty_ldisc_deref(ld);
+       spin_unlock_irqrestore(&ch->ch_lock, flags);
 }
 
 
@@ -1773,10 +1770,8 @@ static int dgnc_tty_write(struct tty_struct *tty,
        /*
         * Bail if no space left.
         */
-       if (count <= 0) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return 0;
-       }
+       if (count <= 0)
+               goto exit_retry;
 
        /*
         * Output the printer ON string, if we are in terminal mode, but
@@ -1803,10 +1798,8 @@ static int dgnc_tty_write(struct tty_struct *tty,
        /*
         * If there is nothing left to copy, or I can't handle any more data, 
leave.
         */
-       if (count <= 0) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               return 0;
-       }
+       if (count <= 0)
+               goto exit_retry;
 
        if (from_user) {
 
@@ -1892,6 +1885,11 @@ static int dgnc_tty_write(struct tty_struct *tty,
        }
 
        return count;
+
+exit_retry:
+
+       spin_unlock_irqrestore(&ch->ch_lock, flags);
+       return 0;
 }
 
 
-- 
1.9.1

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