Char: isicom, cleanup locking

Don't spin processor when not needed (use sleep instead of delay).  Don't
release the lock when needed in next iteration -- this actually fixes a bug --
missing braces

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 27 insertions, 38 deletions

diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c
index 761f77740d67..b133b92a0ad5 100644
--- a/drivers/char/isicom.c
+++ b/drivers/char/isicom.c
@@ -243,17 +243,18 @@ static inline int WaitTillCardIsFree(u16 base)
 
 static int lock_card(struct isi_board *card)
 {
-        char            retries;
         unsigned long base = card->base;
+        unsigned int retries, a;
 
-        for (retries = 0; retries < 100; retries++) {
+        for (retries = 0; retries < 10; retries++) {
                 spin_lock_irqsave(&card->card_lock, card->flags);
-                if (inw(base + 0xe) & 0x1) {
-                        return 1;
-                } else {
-                        spin_unlock_irqrestore(&card->card_lock, card->flags);
-                        udelay(1000);   /* 1ms */
+                for (a = 0; a < 10; a++) {
+                        if (inw(base + 0xe) & 0x1)
+                                return 1;
+                        udelay(10);
                 }
+                spin_unlock_irqrestore(&card->card_lock, card->flags);
+                msleep(10);
         }
         printk(KERN_WARNING "ISICOM: Failed to lock Card (0x%lx)\n",
                 card->base);
@@ -261,23 +262,6 @@ static int lock_card(struct isi_board *card)
         return 0;       /* Failed to acquire the card! */
 }
 
-static int lock_card_at_interrupt(struct isi_board *card)
-{
-        unsigned char           retries;
-        unsigned long base = card->base;
-
-        for (retries = 0; retries < 200; retries++) {
-                spin_lock_irqsave(&card->card_lock, card->flags);
-
-                if (inw(base + 0xe) & 0x1)
-                        return 1;
-                else
-                        spin_unlock_irqrestore(&card->card_lock, card->flags);
-        }
-        /* Failing in interrupt is an acceptable event */
-        return 0;       /* Failed to acquire the card! */
-}
-
 static void unlock_card(struct isi_board *card)
 {
         spin_unlock_irqrestore(&card->card_lock, card->flags);
@@ -415,6 +399,8 @@ static inline int __isicom_paranoia_check(struct isi_port const *port,
 
 static void isicom_tx(unsigned long _data)
 {
+        unsigned long flags;
+        unsigned int retries;
         short count = (BOARD_COUNT-1), card, base;
         short txcount, wrd, residue, word_count, cnt;
         struct isi_port *port;
@@ -435,32 +421,34 @@ static void isicom_tx(unsigned long _data)
         count = isi_card[card].port_count;
         port = isi_card[card].ports;
         base = isi_card[card].base;
+
+        spin_lock_irqsave(&isi_card[card].card_lock, flags);
+        for (retries = 0; retries < 100; retries++) {
+                if (inw(base + 0xe) & 0x1)
+                        break;
+                udelay(2);
+        }
+        if (retries >= 100)
+                goto unlock;
+
         for (;count > 0;count--, port++) {
-                if (!lock_card_at_interrupt(&isi_card[card]))
-                        continue;
                 /* port not active or tx disabled to force flow control */
                 if (!(port->flags & ASYNC_INITIALIZED) ||
                                 !(port->status & ISI_TXOK))
-                        unlock_card(&isi_card[card]);
                         continue;
 
                 tty = port->tty;
 
-
-                if (tty == NULL) {
-                        unlock_card(&isi_card[card]);
+                if (tty == NULL)
                         continue;
-                }
 
                 txcount = min_t(short, TX_SIZE, port->xmit_cnt);
-                if (txcount <= 0 || tty->stopped || tty->hw_stopped) {
-                        unlock_card(&isi_card[card]);
+                if (txcount <= 0 || tty->stopped || tty->hw_stopped)
                         continue;
-                }
-                if (!(inw(base + 0x02) & (1 << port->channel))) {
-                        unlock_card(&isi_card[card]);
+
+                if (!(inw(base + 0x02) & (1 << port->channel)))
                         continue;
-                }
+
                 pr_dbg("txing %d bytes, port%d.\n", txcount,
                         port->channel + 1);
                 outw((port->channel << isi_card[card].shift_count) | txcount,
@@ -508,9 +496,10 @@ static void isicom_tx(unsigned long _data)
                         port->status &= ~ISI_TXOK;
                 if (port->xmit_cnt <= WAKEUP_CHARS)
                         tty_wakeup(tty);
-                unlock_card(&isi_card[card]);
         }
 
+unlock:
+        spin_unlock_irqrestore(&isi_card[card].card_lock, flags);
         /*      schedule another tx for hopefully in about 10ms */
 sched_again:
         if (!re_schedule) {