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MFi386: don't fake the time counter when the debugger is active.

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This breaks the fundamental property of DELAY(). Instead, avoid
grabbing clock_lock when kdb_active is non-zero.
This commit is contained in:
marcel 2004-07-10 22:42:22 +00:00
parent 5d30d6766f
commit 1339cad36a
1 changed files with 12 additions and 20 deletions
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32
sys/amd64/isa/clock.c
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@ -54,6 +54,7 @@ __FBSDID("$FreeBSD$");
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/kdb.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/timetc.h>
@ -292,18 +293,8 @@ DELAY(int n)
* takes about 1.5 usec for each of the i/o's in getit(). The loop
* takes about 6 usec on a 486/33 and 13 usec on a 386/20. The
* multiplications and divisions to scale the count take a while).
*
* However, if ddb is active then use a fake counter since reading
* the i8254 counter involves acquiring a lock. ddb must not go
* locking for many reasons, but it calls here for at least atkbd
* input.
*/
#ifdef DDB
if (db_active)
prev_tick = 0;
else
#endif
prev_tick = getit();
prev_tick = getit();
n -= 0; /* XXX actually guess no initial overhead */
/*
* Calculate (n * (timer_freq / 1e6)) without using floating point
@ -330,13 +321,7 @@ DELAY(int n)
/ 1000000;
while (ticks_left > 0) {
#ifdef DDB
if (db_active) {
inb(0x84);
tick = prev_tick + 1;
} else
#endif
tick = getit();
tick = getit();
#ifdef DELAYDEBUG
++getit_calls;
#endif
@ -381,10 +366,17 @@ sysbeep(int pitch, int period)
splx(x);
return (-1); /* XXX Should be EBUSY, but nobody cares anyway. */
}
mtx_lock_spin(&clock_lock);
#ifdef KDB
if (!kdb_active)
#endif
mtx_lock_spin(&clock_lock);
outb(TIMER_CNTR2, pitch);
outb(TIMER_CNTR2, (pitch>>8));
mtx_unlock_spin(&clock_lock);
#ifdef KDB
if (!kdb_active)
#endif
mtx_unlock_spin(&clock_lock);
if (!beeping) {
/* enable counter2 output to speaker */
outb(IO_PPI, inb(IO_PPI) | 3);