[TEST] fix sleep on 2.6.4

[Benjamin Herrenschmidt]

People who have problems with sleep on 2.6.4, this fix corrects a
bug in pmac_zilog, please let me know if it helps.

Ben.

===== drivers/serial/pmac_zilog.c 1.6 vs edited =====
--- 1.6/drivers/serial/pmac_zilog.c     Sat Mar 13 11:56:12 2004
+++ edited/drivers/serial/pmac_zilog.c  Wed Mar 17 10:54:55 2004
@@ -34,7 +34,7 @@
  *         - maybe put something right into uap->clk_divisor
  */
 
-#undef DEBUG
+#define DEBUG
 #undef DEBUG_HARD
 
 #include <linux/config.h>
@@ -1564,15 +1564,21 @@
 static int pmz_suspend(struct macio_dev *mdev, u32 pm_state)
 {
        struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
-       struct uart_state *state = pmz_uart_reg.state + uap->port.line;
+       struct uart_state *state;
        unsigned long flags;
 
-       if (uap == NULL)
+       if (uap == NULL) {
+               printk("HRM... pmz_suspend with NULL uap\n");
                return 0;
+       }
 
        if (pm_state == mdev->ofdev.dev.power_state || pm_state < 2)
                return 0;
 
+       pmz_debug("suspend, switching to state %d\n", pm_state);
+
+       state = pmz_uart_reg.state + uap->port.line;
+
        down(&pmz_irq_sem);
        down(&state->sem);
 
@@ -1608,6 +1614,8 @@
        up(&state->sem);
        up(&pmz_irq_sem);
 
+       pmz_debug("suspend, switching complete\n");
+
        mdev->ofdev.dev.power_state = pm_state;
 
        return 0;
@@ -1617,7 +1625,7 @@
 static int pmz_resume(struct macio_dev *mdev)
 {
        struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
-       struct uart_state *state = pmz_uart_reg.state + uap->port.line;
+       struct uart_state *state;
        unsigned long flags;
        int pwr_delay;
 
@@ -1627,6 +1635,10 @@
        if (mdev->ofdev.dev.power_state == 0)
                return 0;
        
+       pmz_debug("resume, switching to state 0\n");
+
+       state = pmz_uart_reg.state + uap->port.line;
+
        down(&pmz_irq_sem);
        down(&state->sem);
 
@@ -1659,6 +1671,7 @@
                enable_irq(uap->port.irq);
        }
 
+ bail:
        up(&state->sem);
        up(&pmz_irq_sem);
 
@@ -1671,7 +1684,8 @@
                schedule_timeout((pwr_delay * HZ)/1000);
        }
 
- bail:
+       pmz_debug("resume, switching complete\n");
+
        mdev->ofdev.dev.power_state = 0;
 
        return 0;