From 24bfa950f114d5d770e482de73cf673a3b017f65 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 14 Feb 2014 00:50:34 -0500 Subject: intel_idle: allow sparse sub-state numbering, for Bay Trail Like acpi_idle, intel_idle compared sub-state numbers to the number of supported sub-states -- discarding sub-states numbers that were numbered >= the number of states. But some Bay Trail SOCs use sparse sub-state numbers, so we can't make such a comparison if we are going to access those states. So now we simply check that _some_ sub-states are supported for the given state, and assume that the sub-state number in our driver is valid. In practice, the driver is correct, and even if it were not, the hardware clips invalid sub-state requests to valid ones. No entries in the driver require this change, but Bay Trail will need it. Signed-off-by: Len Brown --- drivers/idle/intel_idle.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'drivers/idle') diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 8e1939f564f4..057ffef37b42 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -584,7 +584,7 @@ static int __init intel_idle_cpuidle_driver_init(void) drv->state_count = 1; for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) { - int num_substates, mwait_hint, mwait_cstate, mwait_substate; + int num_substates, mwait_hint, mwait_cstate; if (cpuidle_state_table[cstate].enter == NULL) break; @@ -597,14 +597,13 @@ static int __init intel_idle_cpuidle_driver_init(void) mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags); mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint); - mwait_substate = MWAIT_HINT2SUBSTATE(mwait_hint); - /* does the state exist in CPUID.MWAIT? */ + /* number of sub-states for this state in CPUID.MWAIT */ num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4)) & MWAIT_SUBSTATE_MASK; - /* if sub-state in table is not enumerated by CPUID */ - if ((mwait_substate + 1) > num_substates) + /* if NO sub-states for this state in CPUID, skip it */ + if (num_substates == 0) continue; if (((mwait_cstate + 1) > 2) && -- cgit v1.2.3