From: Thomas Schlichter <thomas.schlichter@web.de>
Date: Tue, 31 Mar 2015 18:24:39 +0000 (+0200)
Subject: cpuidle: ACPI: do not overwrite name and description of C0
X-Git-Tag: v3.19.5~32
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0cb36a7f1174bc7cb23ff4571131af824e66551;p=thirdparty%2Fkernel%2Fstable.git

cpuidle: ACPI: do not overwrite name and description of C0

commit c7e8bdf5872c5a8f5a6494e16fe839c38a0d3d3d upstream.

Fix a bug that leads to showing the name and description of C-state C0
as "<null>" in sysfs after the ACPI C-states changed (e.g. after AC->DC
or DC->AC
transition).

The function poll_idle_init() in drivers/cpuidle/driver.c initializes the
state 0 during cpuidle_register_driver(), so we better do not overwrite it
again with '\0' during acpi_processor_cst_has_changed().

Signed-off-by: Thomas Schlichter <thomas.schlichter@web.de>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 87b704e41877d..b27ab7a0741de 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -962,7 +962,7 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
 		return -EINVAL;
 
 	drv->safe_state_index = -1;
-	for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
+	for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
 		drv->states[i].name[0] = '\0';
 		drv->states[i].desc[0] = '\0';
 	}