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/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 088ea74..69102ca 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -218,16 +218,23 @@
return sprintf(buf, "%u\n", state->_name);\
}
-static ssize_t show_state_name(struct cpuidle_state *state, char *buf)
-{
- return sprintf(buf, "%s\n", state->name);
+#define define_show_state_str_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
+{ \
+ if (state->_name[0] == '\0')\
+ return sprintf(buf, "<null>\n");\
+ return sprintf(buf, "%s\n", state->_name);\
}
define_show_state_function(exit_latency)
define_show_state_function(power_usage)
define_show_state_function(usage)
define_show_state_function(time)
+define_show_state_str_function(name)
+define_show_state_str_function(desc)
+
define_one_state_ro(name, show_state_name);
+define_one_state_ro(desc, show_state_desc);
define_one_state_ro(latency, show_state_exit_latency);
define_one_state_ro(power, show_state_power_usage);
define_one_state_ro(usage, show_state_usage);
@@ -235,6 +242,7 @@
static struct attribute *cpuidle_state_default_attrs[] = {
&attr_name.attr,
+ &attr_desc.attr,
&attr_latency.attr,
&attr_power.attr,
&attr_usage.attr,