4 files changed, 19 insertions, 3 deletions
diff --git a/firmware/export/config-ipod4g.h b/firmware/export/config-ipod4g.h
index 7e428de..d4d4f28 100644
--- a/firmware/export/config-ipod4g.h
+++ b/firmware/export/config-ipod4g.h
@@ -94,7 +94,7 @@
 #define CONFIG_LED LED_VIRTUAL
 
 /* Define this if you have adjustable CPU frequency */
-//#define HAVE_ADJUSTABLE_CPU_FREQ
+#define HAVE_ADJUSTABLE_CPU_FREQ
 
 #define BOOTFILE_EXT "ipod"
 #define BOOTFILE "rockbox." BOOTFILE_EXT
diff --git a/firmware/export/config-ipodcolor.h b/firmware/export/config-ipodcolor.h
index 9cbc058..a48bde5 100644
--- a/firmware/export/config-ipodcolor.h
+++ b/firmware/export/config-ipodcolor.h
@@ -93,7 +93,7 @@
 #define CONFIG_LED LED_VIRTUAL
 
 /* Define this if you have adjustable CPU frequency */
-//#define HAVE_ADJUSTABLE_CPU_FREQ
+#define HAVE_ADJUSTABLE_CPU_FREQ
 
 #define BOOTFILE_EXT "ipod"
 #define BOOTFILE "rockbox." BOOTFILE_EXT
diff --git a/firmware/export/config-ipodmini.h b/firmware/export/config-ipodmini.h
index 4514bcb..1cb18a7 100644
--- a/firmware/export/config-ipodmini.h
+++ b/firmware/export/config-ipodmini.h
@@ -94,7 +94,7 @@
 #define CONFIG_LED LED_VIRTUAL
 
 /* Define this if you have adjustable CPU frequency */
-//#define HAVE_ADJUSTABLE_CPU_FREQ
+#define HAVE_ADJUSTABLE_CPU_FREQ
 
 #define BOOTFILE_EXT "ipod"
 #define BOOTFILE "rockbox." BOOTFILE_EXT
diff --git a/firmware/system.c b/firmware/system.c
index efa0a06..c957ad9 100644
--- a/firmware/system.c
+++ b/firmware/system.c
@@ -1224,11 +1224,27 @@ void set_cpu_frequency(long frequency)
 
     /* Clock frequency = (24/8)*postmult */
     outl(0xaa020000 | 8 | (postmult << 8), 0x60006034);
+
     /* Wait for PLL relock? */
     udelay(2000);
 
     /* Select PLL as clock source? */
     outl((inl(0x60006020) & 0x0fffff0f) | 0x20000070, 0x60006020);
+
+#if defined(IPOD_COLOR) || defined(IPOD_4G) || defined(IPOD_MINI)
+    /* We don't know why the timer interrupt gets disabled on the PP5020
+       based ipods, but without the following line, the 4Gs will freeze
+       when CPU frequency changing is enabled.  
+
+       Note also that a simple "CPU_INT_EN = TIMER1_MASK;" (as used
+       elsewhere to enable interrupts) doesn't work, we need "|=".
+
+       It's not needed on the PP5021 and PP5022 ipods.
+    */
+
+    /* unmask interrupt source */
+    CPU_INT_EN |= TIMER1_MASK;
+#endif
 }
 #elif !defined(BOOTLOADER)
 void ipod_set_cpu_frequency(void)