RE: Problems in cpuidle
-Original Message-
From: Kevin Hilman [mailto:khil...@deeprootsystems.com]
Sent: Tuesday, March 10, 2009 8:45 PM
To: Premi, Sanjeev
Cc: Högander Jouni; linux-omap@vger.kernel.org
Subject: Re: Problems in cpuidle
Premi, Sanjeev pr...@ti.com writes:
-Original Message-
From: Högander Jouni [mailto:jouni.hogan...@nokia.com]
Sent: Monday, March 09, 2009 3:36 PM
To: Premi, Sanjeev
Cc: linux-omap@vger.kernel.org
Subject: Re: Problems in cpuidle
ext Premi, Sanjeev pr...@ti.com writes:
While working with cpuidle, I have come across these problems.
I am also working on the solutions, but would be good to
hear more
thoughts.
1) The flag 'enable_dyn_sleep' is honoured only in
omap3_idle_bm_check()
but in the C1 state, omap3_enter_idle() is invoked directly.
So, the system can transition to deeper idle state(s)
Same is the case with 'sleep_block'.
Possible Solutions:
a) Call omap3_can_sleep() in omap3_enter_idle().
This makes omap3_idle_bm_check() redundant; and
can be removed.
b) Make single entry point for all idle states
But would be an overkill for C1 state.
c) Change omap3_can_sleep() to check for
omap_uart_can_sleep()
and omap3_fclks_active() only.
Move check for 'enable_dyn_sleep' and 'sleep_block' into
omap3_enter_idle()
I believe (c) would be the most optimal.
Selecting (c) will break traditional pm_idle. Current plan
is to add
one more C state (C1) which would prevent mpu/core sleep
transitions.
Then remove fclk_active check completely.
[sp] I meant doing the same for pm_idle as well.
Also, the new cstate will not help with 'sleep' block.
The proposed change look like:
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c
b/arch/arm/mach-omap2/cpuidle34xx index 7fc3cb3..c25158c 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -82,6 +82,11 @@ static int omap3_enter_idle(struct
cpuidle_device *dev,
/* Used to keep track of the total time in idle */
getnstimeofday(ts_preidle);
+ if (!enable_dyn_sleep)
+ goto return_sleep_time;
+ if (atomic_read(sleep_block) 0)
+ goto return_sleep_time;
+
/*
* Adjust the idle state (if required).
* Also, ensure that usage statistics of correct
state are updated.
diff --git a/arch/arm/mach-omap2/pm34xx.c
b/arch/arm/mach-omap2/pm34xx.c index 0716d60..5c7819a 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -476,14 +476,10 @@ static int omap3_fclks_active(void)
int omap3_can_sleep(void)
{
- if (!enable_dyn_sleep)
- return 0;
if (!omap_uart_can_sleep())
return 0;
if (omap3_fclks_active())
return 0;
- if (atomic_read(sleep_block) 0)
- return 0;
return 1;
}
@@ -534,6 +530,11 @@ err:
static void omap3_pm_idle(void)
{
+ if (!enable_dyn_sleep)
+ return;
+ if (atomic_read(sleep_block) 0)
+ return;
+
local_irq_disable();
local_fiq_disable();
Sanjeev,
I think it's cleaner to just make all the states go through
the 'bm_check', so the standard PM idle and CPUidle use the
same paths.
[sp] I was trying to avoid duplicate code.
When all states go thru bm_check, omap3_enter_idle_bm() and
omap3_enter_idle() can be collapsed into single function.
Your thoughts?
Kevin
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Re: Problems in cpuidle
Premi, Sanjeev pr...@ti.com writes:
-Original Message-
From: Högander Jouni [mailto:jouni.hogan...@nokia.com]
Sent: Monday, March 09, 2009 3:36 PM
To: Premi, Sanjeev
Cc: linux-omap@vger.kernel.org
Subject: Re: Problems in cpuidle
ext Premi, Sanjeev pr...@ti.com writes:
While working with cpuidle, I have come across these problems.
I am also working on the solutions, but would be good to hear more
thoughts.
1) The flag 'enable_dyn_sleep' is honoured only in
omap3_idle_bm_check()
but in the C1 state, omap3_enter_idle() is invoked directly.
So, the system can transition to deeper idle state(s)
Same is the case with 'sleep_block'.
Possible Solutions:
a) Call omap3_can_sleep() in omap3_enter_idle().
This makes omap3_idle_bm_check() redundant; and
can be removed.
b) Make single entry point for all idle states
But would be an overkill for C1 state.
c) Change omap3_can_sleep() to check for omap_uart_can_sleep()
and omap3_fclks_active() only.
Move check for 'enable_dyn_sleep' and 'sleep_block' into
omap3_enter_idle()
I believe (c) would be the most optimal.
Selecting (c) will break traditional pm_idle. Current plan is
to add one more C state (C1) which would prevent mpu/core
sleep transitions. Then remove fclk_active check completely.
[sp] I meant doing the same for pm_idle as well.
Also, the new cstate will not help with 'sleep' block.
The proposed change look like:
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c
b/arch/arm/mach-omap2/cpuidle34xx
index 7fc3cb3..c25158c 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -82,6 +82,11 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
/* Used to keep track of the total time in idle */
getnstimeofday(ts_preidle);
+ if (!enable_dyn_sleep)
+ goto return_sleep_time;
+ if (atomic_read(sleep_block) 0)
+ goto return_sleep_time;
+
/*
* Adjust the idle state (if required).
* Also, ensure that usage statistics of correct state are updated.
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 0716d60..5c7819a 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -476,14 +476,10 @@ static int omap3_fclks_active(void)
int omap3_can_sleep(void)
{
- if (!enable_dyn_sleep)
- return 0;
if (!omap_uart_can_sleep())
return 0;
if (omap3_fclks_active())
return 0;
- if (atomic_read(sleep_block) 0)
- return 0;
return 1;
}
@@ -534,6 +530,11 @@ err:
static void omap3_pm_idle(void)
{
+ if (!enable_dyn_sleep)
+ return;
+ if (atomic_read(sleep_block) 0)
+ return;
+
local_irq_disable();
local_fiq_disable();
Sanjeev,
I think it's cleaner to just make all the states go through the 'bm_check',
so the standard PM idle and CPUidle use the same paths.
Kevin
--
To unsubscribe from this list: send the line unsubscribe linux-omap in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Problems in cpuidle
ext Premi, Sanjeev pr...@ti.com writes: While working with cpuidle, I have come across these problems. I am also working on the solutions, but would be good to hear more thoughts. 1) The flag 'enable_dyn_sleep' is honoured only in omap3_idle_bm_check() but in the C1 state, omap3_enter_idle() is invoked directly. So, the system can transition to deeper idle state(s) Same is the case with 'sleep_block'. Possible Solutions: a) Call omap3_can_sleep() in omap3_enter_idle(). This makes omap3_idle_bm_check() redundant; and can be removed. b) Make single entry point for all idle states But would be an overkill for C1 state. c) Change omap3_can_sleep() to check for omap_uart_can_sleep() and omap3_fclks_active() only. Move check for 'enable_dyn_sleep' and 'sleep_block' into omap3_enter_idle() I believe (c) would be the most optimal. Selecting (c) will break traditional pm_idle. Current plan is to add one more C state (C1) which would prevent mpu/core sleep transitions. Then remove fclk_active check completely. -- Jouni Högander -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: Problems in cpuidle
-Original Message-
From: Högander Jouni [mailto:jouni.hogan...@nokia.com]
Sent: Monday, March 09, 2009 3:36 PM
To: Premi, Sanjeev
Cc: linux-omap@vger.kernel.org
Subject: Re: Problems in cpuidle
ext Premi, Sanjeev pr...@ti.com writes:
While working with cpuidle, I have come across these problems.
I am also working on the solutions, but would be good to hear more
thoughts.
1) The flag 'enable_dyn_sleep' is honoured only in
omap3_idle_bm_check()
but in the C1 state, omap3_enter_idle() is invoked directly.
So, the system can transition to deeper idle state(s)
Same is the case with 'sleep_block'.
Possible Solutions:
a) Call omap3_can_sleep() in omap3_enter_idle().
This makes omap3_idle_bm_check() redundant; and
can be removed.
b) Make single entry point for all idle states
But would be an overkill for C1 state.
c) Change omap3_can_sleep() to check for omap_uart_can_sleep()
and omap3_fclks_active() only.
Move check for 'enable_dyn_sleep' and 'sleep_block' into
omap3_enter_idle()
I believe (c) would be the most optimal.
Selecting (c) will break traditional pm_idle. Current plan is
to add one more C state (C1) which would prevent mpu/core
sleep transitions. Then remove fclk_active check completely.
[sp] I meant doing the same for pm_idle as well.
Also, the new cstate will not help with 'sleep' block.
The proposed change look like:
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx
index 7fc3cb3..c25158c 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -82,6 +82,11 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
/* Used to keep track of the total time in idle */
getnstimeofday(ts_preidle);
+ if (!enable_dyn_sleep)
+ goto return_sleep_time;
+ if (atomic_read(sleep_block) 0)
+ goto return_sleep_time;
+
/*
* Adjust the idle state (if required).
* Also, ensure that usage statistics of correct state are updated.
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 0716d60..5c7819a 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -476,14 +476,10 @@ static int omap3_fclks_active(void)
int omap3_can_sleep(void)
{
- if (!enable_dyn_sleep)
- return 0;
if (!omap_uart_can_sleep())
return 0;
if (omap3_fclks_active())
return 0;
- if (atomic_read(sleep_block) 0)
- return 0;
return 1;
}
@@ -534,6 +530,11 @@ err:
static void omap3_pm_idle(void)
{
+ if (!enable_dyn_sleep)
+ return;
+ if (atomic_read(sleep_block) 0)
+ return;
+
local_irq_disable();
local_fiq_disable();
--
Jouni Högander
--
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the body of a message to majord...@vger.kernel.org
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