1 files changed, 29 insertions, 3 deletions

diff --git a/drivers/net/e100.c b/drivers/net/e100.c
index 22cd04556707..23de22631c64 100644
--- a/drivers/net/e100.c
+++ b/drivers/net/e100.c
@@ -132,6 +132,10 @@
  *      TODO:
  *      o several entry points race with dev->close
  *      o check for tx-no-resources/stop Q races with tx clean/wake Q
+ *
+ *      FIXES:
+ * 2005/12/02 - Michael O'Donnell <Michael.ODonnell at stratus dot com>
+ *      - Stratus87247: protect MDI control register manipulations
  */
 
 #include <linux/config.h>
@@ -578,6 +582,7 @@ struct nic {
         u16 leds;
         u16 eeprom_wc;
         u16 eeprom[256];
+        spinlock_t mdio_lock;
 };
 
 static inline void e100_write_flush(struct nic *nic)
@@ -876,15 +881,35 @@ static u16 mdio_ctrl(struct nic *nic, u32 addr, u32 dir, u32 reg, u16 data)
 {
         u32 data_out = 0;
         unsigned int i;
+        unsigned long flags;
 
+
+        /*
+         * Stratus87247: we shouldn't be writing the MDI control
+         * register until the Ready bit shows True.  Also, since
+         * manipulation of the MDI control registers is a multi-step
+         * procedure it should be done under lock.
+         */
+        spin_lock_irqsave(&nic->mdio_lock, flags);
+        for (i = 100; i; --i) {
+                if (readl(&nic->csr->mdi_ctrl) & mdi_ready)
+                        break;
+                udelay(20);
+        }
+        if (unlikely(!i)) {
+                printk("e100.mdio_ctrl(%s) won't go Ready\n",
+                        nic->netdev->name );
+                spin_unlock_irqrestore(&nic->mdio_lock, flags);
+                return 0;               /* No way to indicate timeout error */
+        }
         writel((reg << 16) | (addr << 21) | dir | data, &nic->csr->mdi_ctrl);
 
-        for(i = 0; i < 100; i++) {
+        for (i = 0; i < 100; i++) {
                 udelay(20);
-                if((data_out = readl(&nic->csr->mdi_ctrl)) & mdi_ready)
+                if ((data_out = readl(&nic->csr->mdi_ctrl)) & mdi_ready)
                         break;
         }
-
+        spin_unlock_irqrestore(&nic->mdio_lock, flags);
         DPRINTK(HW, DEBUG,
                 "%s:addr=%d, reg=%d, data_in=0x%04X, data_out=0x%04X\n",
                 dir == mdi_read ? "READ" : "WRITE", addr, reg, data, data_out);
@@ -2562,6 +2587,7 @@ static int __devinit e100_probe(struct pci_dev *pdev,
         /* locks must be initialized before calling hw_reset */
         spin_lock_init(&nic->cb_lock);
         spin_lock_init(&nic->cmd_lock);
+        spin_lock_init(&nic->mdio_lock);
 
         /* Reset the device before pci_set_master() in case device is in some
          * funky state and has an interrupt pending - hint: we don't have the