Sergei Shtylyov writes:

+       /*
+        * The "classic"  decrementer  interrupts at 0 to -1 transition, while
+        * 40x and book E decrementers interrupt  at 1 to  0 transition.

Funky  spacing .  : )

If I take out the removed lines in the rest of your patch, I get:

+        */
  #if defined(CONFIG_40x)
         mtspr(SPRN_PIT, val);
+#else
+#if !defined(CONFIG_BOOKE)
+       val = val ? val - 1 : 0;
+#endif
+#if defined(CONFIG_8xx_CPU6)
         set_dec_cpu6(val);
+#if defined(CONFIG_PPC_ISERIES)

I think you're missing a #else here.

Paul.