On Mon, May 06, 2002 at 05:17:40PM -0400, Jean-Denis Boyer wrote:
>
> Jim,
>
> I have found a fix for the hanging "Calibrating delay loop...".
>
> I added the following line at the beginning of
> the function "time_init" in arch/ppc/kernel/time.c
>
> set_tb(0, 0);
>
> This resets the time base register and avoids the timer interrupt
> to set the second decrementer value to a very large one.
> It happens only when the TBL is large.
>
> This is a quick fix. Because I think it should work
> for any value of TB. It looks like that part of the code
> does not correctly support the overflow.
>
> Looking through the code, I wonder why the return value of
> the function "tb_delta" is signed.
Hrrm... that definitely seems wrong.
I think this is a signed vs unsigned overflow.
Can you try the following and see if it fixes the problem without the
'set_tb()' quick fix? This should be a more 'correct' fix.
===== time.c 1.42 vs edited =====
--- 1.42/arch/ppc/kernel/time.c Fri Apr 5 12:39:36 2002
+++ edited/time.c Tue May 7 19:40:39 2002
@@ -99,8 +99,8 @@
EXPORT_SYMBOL(rtc_lock);
/* Timer interrupt helper function */
-static inline int tb_delta(unsigned *jiffy_stamp) {
- int delta;
+static inline unsigned tb_delta(unsigned *jiffy_stamp) {
+ unsigned delta;
if (__USE_RTC()) {
delta = get_rtcl();
if (delta < *jiffy_stamp) *jiffy_stamp -= 1000000000;
@@ -150,7 +150,7 @@
*/
int timer_interrupt(struct pt_regs * regs)
{
- int next_dec;
+ unsigned next_dec;
unsigned long cpu = smp_processor_id();
unsigned jiffy_stamp = last_jiffy_stamp(cpu);
extern void do_IRQ(struct pt_regs *);
@@ -258,7 +258,7 @@
void do_settimeofday(struct timeval *tv)
{
unsigned long flags;
- int tb_delta, new_usec, new_sec;
+ unsigned tb_delta, new_usec, new_sec;
write_lock_irqsave(&xtime_lock, flags);
/* Updating the RTC is not the job of this code. If the time is
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