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authorSantosh Shilimkar <santosh.shilimkar@ti.com>2014-05-12 17:37:59 -0400
committerShow Liu <show.liu@linaro.org>2014-06-18 12:05:21 +0800
commitb8ed6e870ad2ace9719d567d122e0724b0e3910c (patch)
tree8687fa8c1e67be477d6597d5bbc20f39daa6022a
parent06838d80d5a345e5194355816c86823c9e92d143 (diff)
downloadlinaro-lsk-b8ed6e870ad2ace9719d567d122e0724b0e3910c.tar.gz
ARM: OMAP4: Fix the boot regression with CPU_IDLE enabled
commit 4b353a706a86598ba47307c47301c3c428b79e09 upstream. On OMAP4 panda board, there have been several bug reports about boot hang and lock-ups with CPU_IDLE enabled. The root cause of the issue is missing interrupts while in idle state. Commit cb7094e8 {cpuidle / omap4 : use CPUIDLE_FLAG_TIMER_STOP flag} moved the broadcast notifiers to common code for right reasons but on OMAP4 which suffers from a nasty ROM code bug with GIC, commit ff999b8a {ARM: OMAP4460: Workaround for ROM bug ..}, we loose interrupts which leads to issues like lock-up, hangs etc. Patch reverts commit cb7094 {cpuidle / omap4 : use CPUIDLE_FLAG_TIMER_STOP flag} and 54769d6 {cpuidle: OMAP4: remove timer broadcast initialization} to avoid the issue. With this change, OMAP4 panda boards, the mentioned issues are getting fixed. We no longer loose interrupts which was the cause of the regression. Fixes: cb7094e8 (cpuidle / omap4 : use CPUIDLE_FLAG_TIMER_STOP flag) Fixes: ff999b8a (cpuidle: OMAP4: remove timer broadcast initialization) Cc: Roger Quadros <rogerq@ti.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Tony Lindgren <tony@atomide.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Reported-tested-by: Roger Quadros <rogerq@ti.com> Reported-tested-by: Kevin Hilman <khilman@linaro.org> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/arm/mach-omap2/cpuidle44xx.c25
1 files changed, 21 insertions, 4 deletions
diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c
index 01fc710c818..2498ab025fa 100644
--- a/arch/arm/mach-omap2/cpuidle44xx.c
+++ b/arch/arm/mach-omap2/cpuidle44xx.c
@@ -14,6 +14,7 @@
#include <linux/cpuidle.h>
#include <linux/cpu_pm.h>
#include <linux/export.h>
+#include <linux/clockchips.h>
#include <asm/cpuidle.h>
#include <asm/proc-fns.h>
@@ -83,6 +84,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
{
struct idle_statedata *cx = state_ptr + index;
u32 mpuss_can_lose_context = 0;
+ int cpu_id = smp_processor_id();
/*
* CPU0 has to wait and stay ON until CPU1 is OFF state.
@@ -110,6 +112,8 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
mpuss_can_lose_context = (cx->mpu_state == PWRDM_POWER_RET) &&
(cx->mpu_logic_state == PWRDM_POWER_OFF);
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);
+
/*
* Call idle CPU PM enter notifier chain so that
* VFP and per CPU interrupt context is saved.
@@ -165,6 +169,8 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
if (dev->cpu == 0 && mpuss_can_lose_context)
cpu_cluster_pm_exit();
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
+
fail:
cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
cpu_done[dev->cpu] = false;
@@ -172,6 +178,16 @@ fail:
return index;
}
+/*
+ * For each cpu, setup the broadcast timer because local timers
+ * stops for the states above C1.
+ */
+static void omap_setup_broadcast_timer(void *arg)
+{
+ int cpu = smp_processor_id();
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &cpu);
+}
+
static struct cpuidle_driver omap4_idle_driver = {
.name = "omap4_idle",
.owner = THIS_MODULE,
@@ -189,8 +205,7 @@ static struct cpuidle_driver omap4_idle_driver = {
/* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
.exit_latency = 328 + 440,
.target_residency = 960,
- .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
- CPUIDLE_FLAG_TIMER_STOP,
+ .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
.enter = omap_enter_idle_coupled,
.name = "C2",
.desc = "CPUx OFF, MPUSS CSWR",
@@ -199,8 +214,7 @@ static struct cpuidle_driver omap4_idle_driver = {
/* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
.exit_latency = 460 + 518,
.target_residency = 1100,
- .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
- CPUIDLE_FLAG_TIMER_STOP,
+ .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
.enter = omap_enter_idle_coupled,
.name = "C3",
.desc = "CPUx OFF, MPUSS OSWR",
@@ -231,5 +245,8 @@ int __init omap4_idle_init(void)
if (!cpu_clkdm[0] || !cpu_clkdm[1])
return -ENODEV;
+ /* Configure the broadcast timer on each cpu */
+ on_each_cpu(omap_setup_broadcast_timer, NULL, 1);
+
return cpuidle_register(&omap4_idle_driver, cpu_online_mask);
}