On 04/30/2014 01:16 AM, Rafael J. Wysocki wrote:
On Tuesday, April 29, 2014 01:28:03 AM Rafael J. Wysocki wrote:
On Monday, April 28, 2014 01:14:32 PM Daniel Lezcano wrote:
On 04/27/2014 02:55 PM, Rafael J. Wysocki wrote:
[ ... ]
---
From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
Subject: cpuidle / menu: Return (-1) if there are no suitable states
If there is a PM QoS latency limit and all of the sufficiently shallow
C-states are disabled, the cpuidle menu governor returns 0 which on
some systems is CPUIDLE_DRIVER_STATE_START and shouldn't be returned
if that C-state has been disabled.
Fix the issue by modifying the menu governor to return (-1) in such
situations.
Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
---
drivers/cpuidle/governors/menu.c | 2 +-
include/linux/cpuidle.h | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)
Index: linux-pm/drivers/cpuidle/governors/menu.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/governors/menu.c
+++ linux-pm/drivers/cpuidle/governors/menu.c
@@ -296,7 +296,7 @@ static int menu_select(struct cpuidle_dr
data->needs_update = 0;
}
- data->last_state_idx = 0;
+ data->last_state_idx = CPUIDLE_DRIVER_STATE_START - 1;
In case of x86, CPUIDLE_DRIVER_STATE_START will be 1, so the select
function could return 0 even this one is disabled and this is not what
you want to happen, no ?
/* Special case when user has set very strict latency requirement */
if (unlikely(latency_req == 0))
--
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