[RE: Regression in intel_idle on Avaton/Rangely Mohon Peak board] On 01/04/2014 (Tue 17:59) Brown, Len wrote:
> > 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. OK, I kept the failing board on loan, since I expected a reply that would contain "can you try this..." :) I will be able to do the above tomorrow (EST). > > > 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. Could be ; I can probably get access to the newer one again too, if that will be useful. > > 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. The dmidecode info I'd posted indicated that the steppings were unnchanged. I can get the /proc/cpuinfo tomorrow, but I figured the dmidecode stepping info was accurate. Is it not reliable? P. -- > > 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/
