1 files changed, 20 insertions, 25 deletions

diff --git a/drivers/ide/pci/cmd64x.c b/drivers/ide/pci/cmd64x.c
index b0d4825c56a9..561197f7b5bb 100644
--- a/drivers/ide/pci/cmd64x.c
+++ b/drivers/ide/pci/cmd64x.c
@@ -1,6 +1,6 @@
 /* $Id: cmd64x.c,v 1.21 2000/01/30 23:23:16
  *
- * linux/drivers/ide/pci/cmd64x.c               Version 1.41    Feb 3, 2007
+ * linux/drivers/ide/pci/cmd64x.c               Version 1.42    Feb 8, 2007
  *
  * cmd64x.c: Enable interrupts at initialization time on Ultra/PCI machines.
  *           Note, this driver is not used at all on other systems because
@@ -189,6 +189,11 @@ static int cmd64x_get_info (char *buffer, char **addr, off_t offset, int count)
 
 #endif  /* defined(DISPLAY_CMD64X_TIMINGS) && defined(CONFIG_PROC_FS) */
 
+static u8 quantize_timing(int timing, int quant)
+{
+        return (timing + quant - 1) / quant;
+}
+
 /*
  * This routine writes the prepared setup/active/recovery counts
  * for a drive into the cmd646 chipset registers to active them.
@@ -268,47 +273,37 @@ static void program_drive_counts (ide_drive_t *drive, int setup_count, int activ
  */
 static u8 cmd64x_tune_pio (ide_drive_t *drive, u8 mode_wanted)
 {
-        int setup_time, active_time, recovery_time;
-        int clock_time, pio_mode, cycle_time;
-        u8 recovery_count2, cycle_count;
-        int setup_count, active_count, recovery_count;
-        int bus_speed = system_bus_clock();
-        ide_pio_data_t  d;
+        int setup_time, active_time, cycle_time;
+        u8  cycle_count, setup_count, active_count, recovery_count;
+        u8  pio_mode;
+        int clock_time = 1000 / system_bus_clock();
+        ide_pio_data_t pio;
 
-        pio_mode = ide_get_best_pio_mode(drive, mode_wanted, 5, &d);
-        cycle_time = d.cycle_time;
+        pio_mode = ide_get_best_pio_mode(drive, mode_wanted, 5, &pio);
+        cycle_time = pio.cycle_time;
 
-        /*
-         * I copied all this complicated stuff from cmd640.c and made a few
-         * minor changes.  For now I am just going to pray that it is correct.
-         */
         setup_time  = ide_pio_timings[pio_mode].setup_time;
         active_time = ide_pio_timings[pio_mode].active_time;
-        recovery_time = cycle_time - (setup_time + active_time);
-        clock_time = 1000 / bus_speed;
-        cycle_count = (cycle_time + clock_time - 1) / clock_time;
-
-        setup_count = (setup_time + clock_time - 1) / clock_time;
 
-        active_count = (active_time + clock_time - 1) / clock_time;
+        setup_count  = quantize_timing( setup_time, clock_time);
+        cycle_count  = quantize_timing( cycle_time, clock_time);
+        active_count = quantize_timing(active_time, clock_time);
 
-        recovery_count = (recovery_time + clock_time - 1) / clock_time;
-        recovery_count2 = cycle_count - (setup_count + active_count);
-        if (recovery_count2 > recovery_count)
-                recovery_count = recovery_count2;
+        recovery_count = cycle_count - active_count;
+        /* program_drive_counts() takes care of zero recovery cycles */
         if (recovery_count > 16) {
                 active_count += recovery_count - 16;
                 recovery_count = 16;
         }
         if (active_count > 16)
-                active_count = 16; /* maximum allowed by cmd646 */
+                active_count = 16; /* maximum allowed by cmd64x */
 
         program_drive_counts (drive, setup_count, active_count, recovery_count);
 
         cmdprintk("%s: PIO mode wanted %d, selected %d (%dns)%s, "
                 "clocks=%d/%d/%d\n",
                 drive->name, mode_wanted, pio_mode, cycle_time,
-                d.overridden ? " (overriding vendor mode)" : "",
+                pio.overridden ? " (overriding vendor mode)" : "",
                 setup_count, active_count, recovery_count);
 
         return pio_mode;