From: Sudeep Holla <sudeep.holla@xxxxxxx>
Instead of allocating 'n-1' states in psci_power_state to manage 'n'
idle states which include "ARM WFI" state, it would be simpler to have
1:1 mapping between psci_power_state and cpuidle driver states.
ARM WFI state(i.e. idx == 0) is handled specially in the generic macro
CPU_PM_CPU_IDLE_ENTER_PARAM and hence state[-1] is not possible. However
for sake of code readability, it is better to have 1:1 mapping and not
use [idx - 1] to access psci_power_state corresponding to driver cpuidle
state for idx.
psci_power_state[0] is default initialised to 0 and is never accessed
while entering WFI state.
Reported-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
Changes in v5:
- None.
---
drivers/cpuidle/cpuidle-psci.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index f3c1a2396f98..361985f52ddd 100644
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -30,7 +30,7 @@ static int psci_enter_idle_state(struct cpuidle_device *dev,
u32 *state = __this_cpu_read(psci_power_state);
return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter,
- idx, state[idx - 1]);
+ idx, state[idx]);
}
static struct cpuidle_driver psci_idle_driver __initdata = {
@@ -89,12 +89,14 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
if (!count)
return -ENODEV;
+ count++; /* Add WFI state too */
psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
if (!psci_states)
return -ENOMEM;
- for (i = 0; i < count; i++) {
- state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
+ for (i = 1; i < count; i++) {
+ state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
+ i - 1);
ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
of_node_put(state_node);
--
2.17.1
