as3525v2: crashless cpufreq switching

delays after modifying the registers seems not to be needed
moving RAM operation (cpu_frequency variable) before modifying the
register also seems to help

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25754 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 3 insertions, 8 deletions

diff --git a/firmware/target/arm/as3525/system-as3525.c b/firmware/target/arm/as3525/system-as3525.c
index 2b3e163611..47cb465c62 100644
--- a/firmware/target/arm/as3525/system-as3525.c
+++ b/firmware/target/arm/as3525/system-as3525.c
@@ -453,34 +453,29 @@ void set_cpu_frequency(long frequency)
 void set_cpu_frequency(long frequency)
 {
     int oldstatus = disable_irq_save();
-    int delay;
+
+    /* We only have 2 settings */
+    cpu_frequency = (frequency == CPUFREQ_MAX) ? frequency : CPUFREQ_NORMAL;
 
     if(frequency == CPUFREQ_MAX)
     {
         /* Change PCLK while FCLK is low, so it doesn't go too high */
         CGU_PERI = (CGU_PERI & ~(0xF << 2)) | (AS3525_PCLK_DIV0 << 2);
 
-        delay = 40; while(delay--) asm("nop");
-
         CGU_PROC = ((AS3525_FCLK_POSTDIV << 4) |
                     (AS3525_FCLK_PREDIV  << 2) |
                     AS3525_FCLK_SEL);
     }
     else
     {
-        frequency = CPUFREQ_NORMAL; /* We only have 2 settings */
-
         CGU_PROC = ((AS3525_FCLK_POSTDIV_UNBOOSTED << 4) |
                     (AS3525_FCLK_PREDIV  << 2) |
                     AS3525_FCLK_SEL);
 
         /* Change PCLK after FCLK is low, so it doesn't go too high */
         CGU_PERI = (CGU_PERI & ~(0xF << 2)) | (AS3525_PCLK_DIV0_UNBOOSTED << 2);
-        delay = 40; while(delay--) asm("nop");
     }
 
-    cpu_frequency = frequency;
-
     restore_irq(oldstatus);
 }
 #endif