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author | Santosh Shilimkar <santosh.shilimkar@ti.com> | 2014-05-12 17:37:59 -0400 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-11 12:03:23 -0700 |
commit | c506847413e50969d24e26bc00595e982796a5dc (patch) | |
tree | 231b00416c2cf93146b836515481c92be671918e | |
parent | 8d1bf0a204da672b10874ba91907ef0492288a7a (diff) | |
download | lwn-c506847413e50969d24e26bc00595e982796a5dc.tar.gz lwn-c506847413e50969d24e26bc00595e982796a5dc.zip |
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.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c index c443f2e97e10..f98410a257e3 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> @@ -80,6 +81,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, int index) { struct idle_statedata *cx = state_ptr + index; + int cpu_id = smp_processor_id(); /* * CPU0 has to wait and stay ON until CPU1 is OFF state. @@ -104,6 +106,8 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, } } + 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. @@ -147,6 +151,8 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, (cx->mpu_logic_state == PWRDM_POWER_OFF)) 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; @@ -154,6 +160,16 @@ 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, @@ -171,8 +187,7 @@ 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", @@ -181,8 +196,7 @@ 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", @@ -213,5 +227,8 @@ 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); } |