[PATCH] DM9000 - spinlock fixes

Fix DM9000 driver usage of spinlocks, which mainly came to light
when running a kernel with spinlock debugging. These come down to:

1) Un-initialised spin lock

2) Several cases of using  spin_xxx(lock) and not spin_xxx(&lock)

3) move the locking around the phy reg for read/write to only
   keep the lock when actually reading or writing to the phy.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 24 insertions, 13 deletions

diff --git a/drivers/net/dm9000.c b/drivers/net/dm9000.c
index 5fddc0ff887..1d92ddd1ec3 100644
--- a/drivers/net/dm9000.c
+++ b/drivers/net/dm9000.c
@@ -48,6 +48,10 @@
  *                        net_device_stats
  *                      * introduced tx_timeout function
  *                      * reworked locking
+ *
+ *        01-Jul-2005   Ben Dooks <ben@simtec.co.uk>
+ *                      * fixed spinlock call without pointer
+ *                      * ensure spinlock is initialised
  */
 
 #include <linux/module.h>
@@ -322,7 +326,7 @@ static void dm9000_timeout(struct net_device *dev)
 
         /* Save previous register address */
         reg_save = readb(db->io_addr);
-        spin_lock_irqsave(db->lock,flags);
+        spin_lock_irqsave(&db->lock,flags);
 
         netif_stop_queue(dev);
         dm9000_reset(db);
@@ -333,7 +337,7 @@ static void dm9000_timeout(struct net_device *dev)
 
         /* Restore previous register address */
         writeb(reg_save, db->io_addr);
-        spin_unlock_irqrestore(db->lock,flags);
+        spin_unlock_irqrestore(&db->lock,flags);
 }
 
 
@@ -405,6 +409,8 @@ dm9000_probe(struct device *dev)
         db = (struct board_info *) ndev->priv;
         memset(db, 0, sizeof (*db));
 
+        spin_lock_init(&db->lock);
+
         if (pdev->num_resources < 2) {
                 ret = -ENODEV;
                 goto out;
@@ -612,7 +618,7 @@ dm9000_open(struct net_device *dev)
 
         /* set and active a timer process */
         init_timer(&db->timer);
-        db->timer.expires  = DM9000_TIMER_WUT * 2;
+        db->timer.expires  = DM9000_TIMER_WUT;
         db->timer.data     = (unsigned long) dev;
         db->timer.function = &dm9000_timer;
         add_timer(&db->timer);
@@ -864,21 +870,11 @@ dm9000_timer(unsigned long data)
 {
         struct net_device *dev = (struct net_device *) data;
         board_info_t *db = (board_info_t *) dev->priv;
-        u8 reg_save;
-        unsigned long flags;
 
         PRINTK3("dm9000_timer()\n");
 
-        spin_lock_irqsave(db->lock,flags);
-        /* Save previous register address */
-        reg_save = readb(db->io_addr);
-
         mii_check_media(&db->mii, netif_msg_link(db), 0);
 
-        /* Restore previous register address */
-        writeb(reg_save, db->io_addr);
-        spin_unlock_irqrestore(db->lock,flags);
-
         /* Set timer again */
         db->timer.expires = DM9000_TIMER_WUT;
         add_timer(&db->timer);
@@ -1098,9 +1094,14 @@ dm9000_phy_read(struct net_device *dev, int phy_reg_unused, int reg)
 {
         board_info_t *db = (board_info_t *) dev->priv;
         unsigned long flags;
+        unsigned int reg_save;
         int ret;
 
         spin_lock_irqsave(&db->lock,flags);
+
+        /* Save previous register address */
+        reg_save = readb(db->io_addr);
+
         /* Fill the phyxcer register into REG_0C */
         iow(db, DM9000_EPAR, DM9000_PHY | reg);
 
@@ -1111,6 +1112,9 @@ dm9000_phy_read(struct net_device *dev, int phy_reg_unused, int reg)
         /* The read data keeps on REG_0D & REG_0E */
         ret = (ior(db, DM9000_EPDRH) << 8) | ior(db, DM9000_EPDRL);
 
+        /* restore the previous address */
+        writeb(reg_save, db->io_addr);
+
         spin_unlock_irqrestore(&db->lock,flags);
 
         return ret;
@@ -1124,9 +1128,13 @@ dm9000_phy_write(struct net_device *dev, int phyaddr_unused, int reg, int value)
 {
         board_info_t *db = (board_info_t *) dev->priv;
         unsigned long flags;
+        unsigned long reg_save;
 
         spin_lock_irqsave(&db->lock,flags);
 
+        /* Save previous register address */
+        reg_save = readb(db->io_addr);
+
         /* Fill the phyxcer register into REG_0C */
         iow(db, DM9000_EPAR, DM9000_PHY | reg);
 
@@ -1138,6 +1146,9 @@ dm9000_phy_write(struct net_device *dev, int phyaddr_unused, int reg, int value)
         udelay(500);            /* Wait write complete */
         iow(db, DM9000_EPCR, 0x0);      /* Clear phyxcer write command */
 
+        /* restore the previous address */
+        writeb(reg_save, db->io_addr);
+
         spin_unlock_irqrestore(&db->lock,flags);
 }