Only use the ichpcib speedstep feature if we're running on a (Mobile) Pentium 4,

since Celerons don't support it.

prodded by gwk@

1 files changed, 31 insertions, 3 deletions

diff --git a/sys/arch/i386/pci/ichpcib.c b/sys/arch/i386/pci/ichpcib.c
index df2410ecf87..bd6f67950ee 100644
--- a/sys/arch/i386/pci/ichpcib.c
+++ b/sys/arch/i386/pci/ichpcib.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ichpcib.c,v 1.11 2006/09/19 00:20:17 brad Exp $	*/
+/*	$OpenBSD: ichpcib.c,v 1.12 2006/11/27 16:27:52 dim Exp $	*/
 /*
  * Copyright (c) 2004 Alexander Yurchenko <grange@openbsd.org>
  *
@@ -38,6 +38,9 @@
 
 #include <dev/pci/ichreg.h>
 
+#include <machine/cpu.h>
+#include <machine/cpufunc.h>
+
 struct ichpcib_softc {
 	struct device sc_dev;
 
@@ -78,6 +81,8 @@ struct cfdriver ichpcib_cd = {
 };
 
 #ifndef SMALL_KERNEL
+extern char *cpu_model;
+static const char p4hint[] = "Mobile Intel(R) Pentium(R) 4";
 static void *ichss_cookie;	/* XXX */
 extern int setperf_prio;
 #endif	/* !SMALL_KERNEL */
@@ -154,14 +159,14 @@ ichpcib_attach(struct device *parent, struct device *self, void *aux)
 		/* Enable SpeedStep */
 		pci_conf_write(pa->pa_pc, pa->pa_tag, ICH_GEN_PMCON1,
 		    pci_conf_read(pa->pa_pc, pa->pa_tag, ICH_GEN_PMCON1) |
-		    ICH_GEN_PMCON1_SS_EN);
+			ICH_GEN_PMCON1_SS_EN);
 
 		/* Hook into hw.setperf sysctl */
 		ichss_cookie = sc;
 		cpu_setperf = ichss_setperf;
 		setperf_prio = 2;
 	}
-#endif	/* !SMALL_KERNEL */
+#endif /* !SMALL_KERNEL */
 
 corepcib:
 	/* Provide core pcib(4) functionality */
@@ -174,10 +179,33 @@ ichss_present(struct pci_attach_args *pa)
 {
 	pcitag_t br_tag;
 	pcireg_t br_id, br_class;
+	struct cpu_info *ci;
+	int family, model, stepping, brandid;
 
 	if (setperf_prio > 2)
 		return (0);
 
+	ci = curcpu();
+	family = (ci->ci_signature >> 8) & 15;
+	model = (ci->ci_signature >> 4) & 15;
+	stepping = ci->ci_signature & 15;
+	brandid = cpu_miscinfo & 0xff; /* XXX should put this in ci */
+
+	/*
+	 * This form of SpeedStep works only on Intel Mobile Pentium 4.
+	 * Intel Celeron processors don't support it.  However, they
+	 * can be coupled with ICH southbridges that do, causing false
+	 * positives.  So we ensure that we are running on Intel Mobile
+	 * Pentium 4.
+	 * This heuristic comes from the Linux speedstep-ich driver.
+	 */
+	if (!(family == 15 && model == 2 &&
+	    ((stepping == 4 && (brandid == 14 || brandid == 15)) ||
+	    (stepping == 7 && brandid == 14) ||
+	    (stepping == 9 && (brandid == 14 || strncasecmp(cpu_model, p4hint,
+	    sizeof(p4hint) - 1) == 0)))))
+		return (0);
+
 	if (PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_INTEL_82801DBM_LPC ||
 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_INTEL_82801CAM_LPC)
 		return (1);