sparc32: improve timer implementation

Timer with zero period (free-run) will never match.

Timer counting starts with tick value of 0x200, not from 0,
so the period must calculated from one tick less than the limit.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This commit is contained in:
Blue Swirl 2010-04-03 06:17:35 +00:00
parent 25da2f343c
commit 68fb89a2c0
1 changed files with 6 additions and 3 deletions

View File

@ -88,8 +88,8 @@ typedef struct TimerContext {
#define TIMER_MAX_COUNT32 0x7ffffe00ULL
#define TIMER_REACHED 0x80000000
#define TIMER_PERIOD 500ULL // 500ns
#define LIMIT_TO_PERIODS(l) ((l) >> 9)
#define PERIODS_TO_LIMIT(l) ((l) << 9)
#define LIMIT_TO_PERIODS(l) (((l) >> 9) - 1)
#define PERIODS_TO_LIMIT(l) (((l) + 1) << 9)
static int slavio_timer_is_user(TimerContext *tc)
{
@ -127,7 +127,10 @@ static void slavio_timer_irq(void *opaque)
slavio_timer_get_out(t);
DPRINTF("callback: count %x%08x\n", t->counthigh, t->count);
t->reached = TIMER_REACHED;
/* if limit is 0 (free-run), there will be no match */
if (t->limit != 0) {
t->reached = TIMER_REACHED;
}
/* there is no interrupt if user timer or free-run */
if (!slavio_timer_is_user(tc) && t->limit != 0) {
qemu_irq_raise(t->irq);