On Fri, Mar 30, 2012 at 6:13 AM, Len Brown <lenb@xxxxxxxxxx> wrote: > From: Julian Anastasov <ja@xxxxxx> > > commit 64b3db22c04586997ab4be46dd5a5b99f8a2d390 (2.6.39), > "Remove use of unreliable FADT revision field" causes regression > for old P4 systems because now cst_control and other fields are > not reset to 0. > > The effect is that acpi_processor_power_init will notice > cst_control != 0 and a write to CST_CNT register is performed > that should not happen. As result, the system oopses after the > "No _CST, giving up" message, sometimes in acpi_ns_internalize_name, > sometimes in acpi_ns_get_type, usually at random places. May be > during migration to CPU 1 in acpi_processor_get_throttling. > > Every one of these settings help to avoid this problem: > - acpi=off > - processor.nocst=1 > - maxcpus=1 > > The fix is to update acpi_gbl_FADT.header.length after > the original value is used to check for old revisions. > > https://bugzilla.kernel.org/show_bug.cgi?id=42700 > https://bugzilla.redhat.com/show_bug.cgi?id=727865 > > Signed-off-by: Julian Anastasov <ja@xxxxxx> > Acked-by: Bob Moore <robert.moore@xxxxxxxxx> > Signed-off-by: Len Brown <len.brown@xxxxxxxxx> This one should go into the stable trees. The bug it fixes causes a number of machines to not boot with anything newer than 2.6.38. josh -- 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
