> I've got an eval board with a 1.7GHz Avaton/C2000 that hangs at boot > shortly after the idle driver registration -- typically 1/2 dozen > dmesg lines later, around rtc init, or net stack init.
Paul, Please boot the failing board with "intel_idle.max_cstate=0" to disable intel_idle entirely, and then show the C-states exported by acpi_idle, that predumably, are stable on both boards: dmesg | grep idle grep . /sys/devices/system/cpu/cpu0/cpuidle/*/* Then go back and boot with "intel_idle.max_cstate=N" where N is incremented by 1 until when the system fails and note the largest N that still works. > The interesting part is that a nearly identical board, but with > different (newer/faster) CPU and newer BIOS doesn't have the hang. Possibly an electrical bug in the earlier board. Maybe they worked around it by disabling a C-state in ACPI and didn't test upstream Linux? I'd be interested in the acpi_idle output above for both the new and old boards to see if they are exporting different states on the two boards. dmidecode isn't useful in this case. The CPUID in /proc/cpuinfo may be useful if the problem turns out to be associated with some stepping. thanks, -Len -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/