diff options
| -rw-r--r-- | sys/dev/acpi/acpihpet.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/sys/dev/acpi/acpihpet.c b/sys/dev/acpi/acpihpet.c index 1a44c1812d3..087fc29a62e 100644 --- a/sys/dev/acpi/acpihpet.c +++ b/sys/dev/acpi/acpihpet.c @@ -1,4 +1,4 @@ -/* $OpenBSD: acpihpet.c,v 1.6 2008/06/11 04:42:09 marco Exp $ */ +/* $OpenBSD: acpihpet.c,v 1.7 2009/01/20 20:23:57 kettenis Exp $ */ /* * Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com> * @@ -91,6 +91,7 @@ acpihpet_attach(struct device *parent, struct device *self, void *aux) struct acpi_hpet *hpet = (struct acpi_hpet *)aaa->aaa_table; u_int64_t period, freq; /* timer period in femtoseconds (10^-15) */ u_int32_t v1, v2; + int timeout; if (acpi_map_address(psc, &hpet->base_address, 0, HPET_REG_SIZE, &sc->sc_ioh, &sc->sc_iot)) { @@ -98,6 +99,26 @@ acpihpet_attach(struct device *parent, struct device *self, void *aux) return; } + /* + * Revisions 0x30 through 0x3a of the AMD SB700, with spread + * spectrum enabled, have an SMM based HPET emulation that's + * subtly broken. The hardware is initialized upon first + * access of the configuration register. Initialization takes + * some time during which the configuration register returns + * 0xffffffff. + */ + timeout = 1000; + do { + if (bus_space_read_4(sc->sc_iot, sc->sc_ioh, + HPET_CONFIGURATION) != 0xffffffff) + break; + } while(--timeout > 0); + + if (timeout == 0) { + printf(": disabled\n"); + return; + } + /* enable hpet */ bus_space_write_4(sc->sc_iot, sc->sc_ioh, HPET_CONFIGURATION, 1); |