reverting guesscpuhz() changes, causes trouble

3 files changed, 14 insertions, 19 deletions

diff --git a/sys/src/9/pc/archacpi.c b/sys/src/9/pc/archacpi.c
index 298709847..24b3245bc 100644
--- a/sys/src/9/pc/archacpi.c
+++ b/sys/src/9/pc/archacpi.c
@@ -519,5 +519,7 @@ identify(void)
 		return 1;
 	if((cp = getconf("*nomp")) != nil && strcmp(cp, "0") != 0)
 		return 1;
+	if(m->havetsc)
+		archacpi.fastclock = tscticks;
 	return 0;
 }
diff --git a/sys/src/9/pc/archmp.c b/sys/src/9/pc/archmp.c
index 354249f38..23cf4fa66 100644
--- a/sys/src/9/pc/archmp.c
+++ b/sys/src/9/pc/archmp.c
@@ -395,5 +395,8 @@ identify(void)
 		return 1;
 	}
 
+	if(m->havetsc)
+		archmp.fastclock = tscticks;
+
 	return 0;
 }
diff --git a/sys/src/9/pc/i8253.c b/sys/src/9/pc/i8253.c
index 46e59f5c4..1ae22615f 100644
--- a/sys/src/9/pc/i8253.c
+++ b/sys/src/9/pc/i8253.c
@@ -145,10 +145,12 @@ guesscpuhz(int aalcycles)
 		 *
 		 */
 		outb(Tmode, Latch2);
+		cycles(&a);
 		x = inb(T2cntr);
 		x |= inb(T2cntr)<<8;
 		aamloop(loops);
 		outb(Tmode, Latch2);
+		cycles(&b);
 		y = inb(T2cntr);
 		y |= inb(T2cntr)<<8;
 
@@ -172,25 +174,13 @@ guesscpuhz(int aalcycles)
 	cpufreq = (vlong)loops*((aalcycles*2*Freq)/x);
 	m->loopconst = (cpufreq/1000)/aalcycles;	/* AAM+LOOP's for 1 ms */
 
-	if(m->havetsc){
-		aamloop(loops);		/* warm up */
-		cycles(&a);
-		aamloop(loops);
-		cycles(&b);
-	
-		aamloop(loops);
-		cycles(&a);
-		aamloop(loops);
-		cycles(&b);
-
-		/* a == b means virtualbox has confused us */
-		if(b > a){
-			b -= a;
-			b *= 2*Freq;
-			b /= x;
-			m->cyclefreq = b;
-			cpufreq = b;
-		}
+	/* a == b means virtualbox has confused us */
+	if(m->havetsc && b > a){
+		b -= a;
+		b *= 2*Freq;
+		b /= x;
+		m->cyclefreq = b;
+		cpufreq = b;
 	}
 	m->cpuhz = cpufreq;