Hey, you can set the maximum C-state to use using the "processor.max_cstate=<value>" parameter. No need to recompile. Best, Dominik On Tue, Nov 24, 2009 at 09:50:01PM +0000, Alex wrote: > I run Ubuntu 8.04.3 LTS server 32bit in a small low power motherboard (VIA LN10000EG) equipped with VIA C7 1GHz CPU. > Kernel 2.6.24 > > I've some problems with serial device: sometimes I've overrun errors when receive data through /dev/ttyS0 > > After some days of hard work I've discovered that when CPU enter in C2 or C3 state and data come in from serial line, I've the overrun. > > I've searched for a solution and I've found that kernel parameter "idle=halt" can avoid CPU enter C2/C3 state, but this parameter is now not supported anymore (it was in the past). > So I've completely disabled the ACPI support ("acpi=off" kernel parameter). > But I lack support for power button, poweroff command and so on. > I wish to re-enable ACPI. > > The question is: Howto avoid CPU enter C2/C3 state and re-activate ACPI so CPU can go in C1 state ? C1 is better than nothing at all .... > > I have no problem to modify kernel source and recompile it. > > Thanks fo suggestions > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html