OMAP3: cpuidle: Update statistics for correct state
When 'enable_off_mode' is 0, the target power state for MPU
and CORE was locally changed to PWRDM_POWER_RET but, the
statistics are updated for idle state originally selected
by the governor.
This patch 'invalidates' the idle states that lead either of
MPU or Core to PWRDM_POWER_OFF state when 'enable_off_mode'
is '0'. The states are valid once 'enable_off_mode' is set
to '1'.
Added function next_valid_state() to check if current state
is valid; else get the next valid state. It is called from
omap3_enter_idle_bm().
Signed-off-by: Sanjeev Premi <premi@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index 12f0cbf..ff1ad3d 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -45,6 +45,8 @@
#define OMAP3_STATE_C6 5 /* C6 - MPU OFF + Core RET */
#define OMAP3_STATE_C7 6 /* C7 - MPU OFF + Core OFF */
+#define OMAP3_STATE_MAX OMAP3_STATE_C7
+
struct omap3_processor_cx {
u8 valid;
u8 type;
@@ -104,13 +106,6 @@
local_irq_disable();
local_fiq_disable();
- if (!enable_off_mode) {
- if (mpu_state < PWRDM_POWER_RET)
- mpu_state = PWRDM_POWER_RET;
- if (core_state < PWRDM_POWER_RET)
- core_state = PWRDM_POWER_RET;
- }
-
pwrdm_set_next_pwrst(mpu_pd, mpu_state);
pwrdm_set_next_pwrst(core_pd, core_state);
@@ -141,6 +136,67 @@
}
/**
+ * next_valid_state - Find next valid c-state
+ * @dev: cpuidle device
+ * @state: Currently selected c-state
+ *
+ * If the current state is valid, it is returned back to the caller.
+ * Else, this function searches for a lower c-state which is still
+ * valid (as defined in omap3_power_states[]).
+ */
+static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
+ struct cpuidle_state *curr)
+{
+ struct cpuidle_state *next = NULL;
+ struct omap3_processor_cx *cx;
+
+ cx = (struct omap3_processor_cx *)cpuidle_get_statedata(curr);
+
+ /* Check if current state is valid */
+ if (cx->valid) {
+ return curr;
+ } else {
+ u8 idx = OMAP3_STATE_MAX;
+
+ /*
+ * Reach the current state starting at highest C-state
+ */
+ for (; idx >= OMAP3_STATE_C1; idx--) {
+ if (&dev->states[idx] == curr) {
+ next = &dev->states[idx];
+ break;
+ }
+ }
+
+ /*
+ * Should never hit this condition.
+ */
+ WARN_ON(next == NULL);
+
+ /*
+ * Drop to next valid state.
+ * Start search from the next (lower) state.
+ */
+ idx--;
+ for (; idx >= OMAP3_STATE_C1; idx--) {
+ struct omap3_processor_cx *cx;
+
+ cx = cpuidle_get_statedata(&dev->states[idx]);
+ if (cx->valid) {
+ next = &dev->states[idx];
+ break;
+ }
+ }
+ /*
+ * C1 and C2 are always valid.
+ * So, no need to check for 'next==NULL' outside this loop.
+ */
+ }
+
+ return next;
+}
+
+/**
* omap3_enter_idle_bm - Checks for any bus activity
* @dev: cpuidle device
* @state: The target state to be programmed
@@ -152,7 +208,7 @@
static int omap3_enter_idle_bm(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
- struct cpuidle_state *new_state = state;
+ struct cpuidle_state *new_state = next_valid_state(dev, state);
if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && omap3_idle_bm_check()) {
BUG_ON(!dev->safe_state);
@@ -165,6 +221,30 @@
DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
+/**
+ * omap3_cpuidle_update_states - Update the cpuidle states.
+ *
+ * Currently, this function toggles the validity of idle states based upon
+ * the flag 'enable_off_mode'. When the flag is set all states are valid.
+ * Else, states leading to OFF state set to be invalid.
+ */
+void omap3_cpuidle_update_states(void)
+{
+ int i;
+
+ for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
+ struct omap3_processor_cx *cx = &omap3_power_states[i];
+
+ if (enable_off_mode) {
+ cx->valid = 1;
+ } else {
+ if ((cx->mpu_state == PWRDM_POWER_OFF) ||
+ (cx->core_state == PWRDM_POWER_OFF))
+ cx->valid = 0;
+ }
+ }
+}
+
/* omap3_init_power_states - Initialises the OMAP3 specific C states.
*
* Below is the desciption of each C state.
@@ -302,6 +382,8 @@
return -EINVAL;
dev->state_count = count;
+ omap3_cpuidle_update_states();
+
if (cpuidle_register_device(dev)) {
printk(KERN_ERR "%s: CPUidle register device failed\n",
__func__);