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ARM: OMAP4: Fix the boot regression with CPU_IDLE enabled

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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: stable@vger.kernel.org # v3.9+
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>
This commit is contained in:
Santosh Shilimkar 2014-05-12 17:37:59 -04:00 committed by Tony Lindgren
parent 9ce2482fc6
commit 4b353a706a
1 changed files with 21 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
arch/arm/mach-omap2/cpuidle44xx.c
View File

@ -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 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev,
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);
}