[PATCH 3.16.y-ckt 018/180] cpuidle: remove state_count field from struct cpuidle_device

From: Luis Henriques
Date: Thu May 07 2015 - 06:48:13 EST


3.16.7-ckt11 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>

commit d75e4af14e228bbe3f86e29bcecb8e6be98d4e04 upstream.

Thomas Schlichter reports the following issue on his Samsung NC20:

"The C-states C1 and C2 to the OS when connected to AC, and additionally
provides the C3 C-state when disconnected from AC. However, the number
of C-states shown in sysfs is fixed to the number of C-states present
at boot.
If I boot with AC connected, I always only see the C-states up to C2
even if I disconnect AC.

The reason is commit 130a5f692425 (ACPI / cpuidle: remove dev->state_count
setting). It removes the update of dev->state_count, but sysfs uses
exactly this variable to show the C-states.

The fix is to use drv->state_count in sysfs. As this is currently the
last user of dev->state_count, this variable can be completely removed."

Remove dev->state_count as per the above.

Reported-by: Thomas Schlichter <thomas.schlichter@xxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
drivers/cpuidle/cpuidle.c | 3 ---
drivers/cpuidle/sysfs.c | 5 +++--
include/linux/cpuidle.h | 1 -
3 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index cb7019977c50..d3185606473a 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -289,9 +289,6 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
if (!dev->registered)
return -EINVAL;

- if (!dev->state_count)
- dev->state_count = drv->state_count;
-
ret = cpuidle_add_device_sysfs(dev);
if (ret)
return ret;
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index efe2f175168f..3368c50ef0ea 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -401,7 +401,7 @@ static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);

/* state statistics */
- for (i = 0; i < device->state_count; i++) {
+ for (i = 0; i < drv->state_count; i++) {
kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
if (!kobj)
goto error_state;
@@ -433,9 +433,10 @@ error_state:
*/
static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
{
+ struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
int i;

- for (i = 0; i < device->state_count; i++)
+ for (i = 0; i < drv->state_count; i++)
cpuidle_free_state_kobj(device, i);
}

diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 25e0df6155a4..575b7166cb08 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -69,7 +69,6 @@ struct cpuidle_device {
unsigned int cpu;

int last_residency;
- int state_count;
struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
struct cpuidle_driver_kobj *kobj_driver;
--
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