diff options
| -rw-r--r-- | firmware/target/arm/tms320dm320/system-dm320.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/firmware/target/arm/tms320dm320/system-dm320.c b/firmware/target/arm/tms320dm320/system-dm320.c index 12e0b6d03d..dc9c2060c6 100644 --- a/firmware/target/arm/tms320dm320/system-dm320.c +++ b/firmware/target/arm/tms320dm320/system-dm320.c @@ -413,13 +413,35 @@ void set_cpu_frequency(long frequency) #endif /* - * Waits for specified amount of microseconds + * Waits for specified amount of microseconds (or longer, but NEVER less) + * + * Maximum supported usec value is 10000, use sleep() for longer delays. */ void udelay(int usec) { + /* + * count and prev_tick must be initialized as soon as posible (right + * after function entry) + * + * count must be initialized before prev_count + */ unsigned short count = IO_TIMER1_TMCNT; + long prev_tick = current_tick; + + /* initialization time/sequence of these values is not critical */ unsigned short stop; unsigned short tmp = IO_TIMER1_TMDIV; - int prev_tick = current_tick; + + if (!irq_enabled()) + { + /* + * Interrupts are disabled + * + * Clear TIMER1 interrupt to prevent returning from this fuction + * before specified amount of time has passed + * In worst case this makes udelay() take one tick longer + */ + IO_INTC_IRQ0 = INTR_IRQ0_TMR1; + } /* * On Sansa Connect tick timer counts from 0 to 26999 @@ -450,13 +472,14 @@ void udelay(int usec) { /* udelay will end after counter reset (tick) */ while ((IO_TIMER1_TMCNT < stop) || ((current_tick == prev_tick) /* ensure new tick */ && - (IO_INTC_IRQ0 & (1 << 1)))); /* prevent lock */ + (IO_INTC_IRQ0 & INTR_IRQ0_TMR1))); /* prevent lock */ } else { /* udelay will end before counter reset (tick) */ while ((IO_TIMER1_TMCNT < stop) && - ((current_tick == prev_tick) && (IO_INTC_IRQ0 & (1 << 1)))); + ((current_tick == prev_tick) && + (IO_INTC_IRQ0 & INTR_IRQ0_TMR1))); } } |