A more complete fix for perf status MSR's (on e.g. Core 2 Duo X6800),

that specify equal highest and lowest clock ratios.  EST is now
silently disabled on these, as was already done for lowest clock
ratios that are zero (on e.g. a bunch of Pentium 4's).

Other weird MSR's are still reported, because we first want to know
about them, before we decide how to handle them.

1 files changed, 18 insertions, 12 deletions

diff --git a/sys/arch/i386/i386/est.c b/sys/arch/i386/i386/est.c
index 51474a989aa..3ed13d6bcf0 100644
--- a/sys/arch/i386/i386/est.c
+++ b/sys/arch/i386/i386/est.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: est.c,v 1.26 2006/12/21 22:31:07 dim Exp $ */
+/*	$OpenBSD: est.c,v 1.27 2006/12/22 01:34:46 dim Exp $ */
 /*
  * Copyright (c) 2003 Michael Eriksson.
  * All rights reserved.
@@ -961,8 +961,9 @@ void
 est_init(const char *cpu_device, int vendor)
 {
 	int i, mhz, mv, low, high;
-	u_int16_t idhi, idlo, cur;
 	u_int64_t msr;
+	u_int16_t idhi, idlo, cur;
+	u_int8_t crhi, crlo, crcur;
 	const struct fqlist *fql;
 
 	if (setperf_prio > 3)
@@ -980,16 +981,25 @@ est_init(const char *cpu_device, int vendor)
 	idhi = (msr >> 32) & 0xffff;
 	idlo = (msr >> 48) & 0xffff;
 	cur = msr & 0xffff;
-	if (idlo == 0) {
+	crhi = (idhi  >> 8) & 0xff;
+	crlo = (idlo  >> 8) & 0xff;
+	crcur = (cur >> 8) & 0xff;
+	if (crlo == 0 || crhi == crlo) {
 		/*
-		 * Don't complain about this case.  It seems to happen
-		 * on all Pentium 4's that report EST.
+		 * Don't complain about these cases, and silently disable EST:
+		 * - A lowest clock ratio of 0, which seems to happen on all
+		 *   Pentium 4's that report EST.
+		 * - An equal highest and lowest clock ratio, which happens on
+		 *   at least the Core 2 Duo X6800, maybe on newer models too.
 		 */
 		return;
 	}
-	if (idhi == 0 || cur == 0 ||
-	    ((cur >> 8) & 0xff) < ((idlo >> 8) & 0xff) ||
-	    ((cur >> 8) & 0xff) > ((idhi >> 8) & 0xff)) {
+	if (crhi == 0 || crcur == 0 || crlo > crhi ||
+	    crcur < crlo || crcur > crhi) {
+		/*
+		 * Do complain about other weirdness, because we first want to
+		 * know about it, before we decide what to do with it.
+		 */
 		printf("%s: EST: strange msr value 0x%016llx\n",
 		    cpu_device, msr);
 		return;
@@ -1049,10 +1059,6 @@ est_init(const char *cpu_device, int vendor)
 	}
 	low = MSR2MHZ(est_fqlist->table[est_fqlist->n - 1], bus_clock);
 	high = MSR2MHZ(est_fqlist->table[0], bus_clock);
-	if (low == high) {
-		printf(": high and low speed are the same, disabling EST\n");
-		return;
-	}
 	perflevel = (mhz - low) * 100 / (high - low);
 
 	/*