Introduce sanity check and extra nop to stabilise TCC780x set_cpu_frequency(). Re-enable HAVE_ADJUSTABLE_CPU_FREQ and kill a few warnings by setting HAVE_SW_TONE_CONTROLS.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16904 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 4 insertions, 3 deletions

diff --git a/firmware/target/arm/tcc780x/system-tcc780x.c b/firmware/target/arm/tcc780x/system-tcc780x.c
index f6392b023a..c109b8ddda 100644
--- a/firmware/target/arm/tcc780x/system-tcc780x.c
+++ b/firmware/target/arm/tcc780x/system-tcc780x.c
@@ -291,11 +291,11 @@ int system_memory_guard(int newmode)
 
 #ifdef HAVE_ADJUSTABLE_CPU_FREQ
 
-/* Note: This is not currently enabled because switching seems to 
-   cause an occasional freeze. To be investigated. */
-
 void set_cpu_frequency(long frequency)
 {
+    if (cpu_frequency == frequency)
+        return;
+    
     /* CPU/COP frequencies can be scaled between Fbus (min) and Fsys (max).
        Fbus should not be set below ~32Mhz with LCD enabled or the display
        will be garbled. */
@@ -327,6 +327,7 @@ void set_cpu_frequency(long frequency)
     asm volatile (
         "nop      \n\t"
         "nop      \n\t"
+        "nop      \n\t"
     );
 
     cpu_frequency = frequency;