ACPI, cpuidle: Clarify C-state description in sysfs
Add a new sysfs entry under cpuidle states. desc - can be used by driver to
communicate to userspace any specific information about the state.
This helps in identifying the exact hardware C-states behind the ACPI C-state
definition.
Idea is to export this through powertop, which will help to map the C-state
reported by powertop to actual hardware C-state.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 32003fd..baa389b9 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -945,11 +945,16 @@
* Otherwise, ignore this info and continue.
*/
cx.entry_method = ACPI_CSTATE_HALT;
+ snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
} else {
continue;
}
+ } else {
+ snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
+ cx.address);
}
+
obj = &(element->package.elements[2]);
if (obj->type != ACPI_TYPE_INTEGER)
continue;
@@ -1643,6 +1648,11 @@
return -EINVAL;
}
+ for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
+ dev->states[i].name[0] = '\0';
+ dev->states[i].desc[0] = '\0';
+ }
+
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
cx = &pr->power.states[i];
state = &dev->states[count];
@@ -1659,6 +1669,7 @@
cpuidle_set_statedata(state, cx);
snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
+ strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
state->exit_latency = cx->latency;
state->target_residency = cx->latency * latency_factor;
state->power_usage = cx->power;