diff mbox

ARM: OMAP4+: SMP: use lockless clkdm/pwrdm api in omap4_boot_secondary

Message ID 1447695533-11460-1-git-send-email-grygorii.strashko@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Grygorii Strashko Nov. 16, 2015, 5:38 p.m. UTC
OMAP CPU hotplug uses cpu1's clocks and power domains for CPU1 wake up
from low power states (or turn on CPU1). This part of code is also
part of system suspend (disable_nonboot_cpus()).
From other side, cpu1's clocks and power domains are used by CPUIdle. All above
functionality is mutually exclusive and, therefore, lockless clkdm/pwrdm api
can be used in omap4_boot_secondary().

This fixes below back-trace on -RT which is triggered by
pwrdm_lock/unlock():

BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917
 in_atomic(): 1, irqs_disabled(): 0, pid: 118, name: sh
 9 locks held by sh/118:
  #0:  (sb_writers#4){.+.+.+}, at: [<c0144a6c>] vfs_write+0x13c/0x164
  #1:  (&of->mutex){+.+.+.}, at: [<c01b4c70>] kernfs_fop_write+0x48/0x19c
  #2:  (s_active#24){.+.+.+}, at: [<c01b4c78>] kernfs_fop_write+0x50/0x19c
  #3:  (device_hotplug_lock){+.+.+.}, at: [<c03cbff0>] lock_device_hotplug_sysfs+0xc/0x4c
  #4:  (&dev->mutex){......}, at: [<c03cd284>] device_online+0x14/0x88
  #5:  (cpu_add_remove_lock){+.+.+.}, at: [<c003af90>] cpu_up+0x50/0x1a0
  #6:  (cpu_hotplug.lock){++++++}, at: [<c003ae48>] cpu_hotplug_begin+0x0/0xc4
  #7:  (cpu_hotplug.lock#2){+.+.+.}, at: [<c003aec0>] cpu_hotplug_begin+0x78/0xc4
  #8:  (boot_lock){+.+...}, at: [<c002b254>] omap4_boot_secondary+0x1c/0x178
 Preemption disabled at:[<  (null)>]   (null)

 CPU: 0 PID: 118 Comm: sh Not tainted 4.1.12-rt11-01998-gb4a62c3-dirty #137
 Hardware name: Generic DRA74X (Flattened Device Tree)
 [<c0017574>] (unwind_backtrace) from [<c0013be8>] (show_stack+0x10/0x14)
 [<c0013be8>] (show_stack) from [<c05a8670>] (dump_stack+0x80/0x94)
 [<c05a8670>] (dump_stack) from [<c05ad158>] (rt_spin_lock+0x24/0x54)
 [<c05ad158>] (rt_spin_lock) from [<c0030dac>] (clkdm_wakeup+0x10/0x2c)
 [<c0030dac>] (clkdm_wakeup) from [<c002b2c0>] (omap4_boot_secondary+0x88/0x178)
 [<c002b2c0>] (omap4_boot_secondary) from [<c0015d00>] (__cpu_up+0xc4/0x164)
 [<c0015d00>] (__cpu_up) from [<c003b09c>] (cpu_up+0x15c/0x1a0)
 [<c003b09c>] (cpu_up) from [<c03cd2d4>] (device_online+0x64/0x88)
 [<c03cd2d4>] (device_online) from [<c03cd360>] (online_store+0x68/0x74)
 [<c03cd360>] (online_store) from [<c01b4ce0>] (kernfs_fop_write+0xb8/0x19c)
 [<c01b4ce0>] (kernfs_fop_write) from [<c0144124>] (__vfs_write+0x20/0xd8)
 [<c0144124>] (__vfs_write) from [<c01449c0>] (vfs_write+0x90/0x164)
 [<c01449c0>] (vfs_write) from [<c01451e4>] (SyS_write+0x44/0x9c)
 [<c01451e4>] (SyS_write) from [<c0010240>] (ret_fast_syscall+0x0/0x54)
 CPU1: smp_ops.cpu_die() returned, trying to resuscitate

Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
 arch/arm/mach-omap2/omap-smp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Tony Lindgren Nov. 25, 2015, 7:03 p.m. UTC | #1
* Grygorii Strashko <grygorii.strashko@ti.com> [151116 09:39]:
> OMAP CPU hotplug uses cpu1's clocks and power domains for CPU1 wake up
> from low power states (or turn on CPU1). This part of code is also
> part of system suspend (disable_nonboot_cpus()).
> >From other side, cpu1's clocks and power domains are used by CPUIdle. All above
> functionality is mutually exclusive and, therefore, lockless clkdm/pwrdm api
> can be used in omap4_boot_secondary().
> 
> This fixes below back-trace on -RT which is triggered by
> pwrdm_lock/unlock():
> 
> BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917
>  in_atomic(): 1, irqs_disabled(): 0, pid: 118, name: sh
>  9 locks held by sh/118:
>   #0:  (sb_writers#4){.+.+.+}, at: [<c0144a6c>] vfs_write+0x13c/0x164
>   #1:  (&of->mutex){+.+.+.}, at: [<c01b4c70>] kernfs_fop_write+0x48/0x19c
>   #2:  (s_active#24){.+.+.+}, at: [<c01b4c78>] kernfs_fop_write+0x50/0x19c
>   #3:  (device_hotplug_lock){+.+.+.}, at: [<c03cbff0>] lock_device_hotplug_sysfs+0xc/0x4c
>   #4:  (&dev->mutex){......}, at: [<c03cd284>] device_online+0x14/0x88
>   #5:  (cpu_add_remove_lock){+.+.+.}, at: [<c003af90>] cpu_up+0x50/0x1a0
>   #6:  (cpu_hotplug.lock){++++++}, at: [<c003ae48>] cpu_hotplug_begin+0x0/0xc4
>   #7:  (cpu_hotplug.lock#2){+.+.+.}, at: [<c003aec0>] cpu_hotplug_begin+0x78/0xc4
>   #8:  (boot_lock){+.+...}, at: [<c002b254>] omap4_boot_secondary+0x1c/0x178
>  Preemption disabled at:[<  (null)>]   (null)
> 
>  CPU: 0 PID: 118 Comm: sh Not tainted 4.1.12-rt11-01998-gb4a62c3-dirty #137
>  Hardware name: Generic DRA74X (Flattened Device Tree)
>  [<c0017574>] (unwind_backtrace) from [<c0013be8>] (show_stack+0x10/0x14)
>  [<c0013be8>] (show_stack) from [<c05a8670>] (dump_stack+0x80/0x94)
>  [<c05a8670>] (dump_stack) from [<c05ad158>] (rt_spin_lock+0x24/0x54)
>  [<c05ad158>] (rt_spin_lock) from [<c0030dac>] (clkdm_wakeup+0x10/0x2c)
>  [<c0030dac>] (clkdm_wakeup) from [<c002b2c0>] (omap4_boot_secondary+0x88/0x178)
>  [<c002b2c0>] (omap4_boot_secondary) from [<c0015d00>] (__cpu_up+0xc4/0x164)
>  [<c0015d00>] (__cpu_up) from [<c003b09c>] (cpu_up+0x15c/0x1a0)
>  [<c003b09c>] (cpu_up) from [<c03cd2d4>] (device_online+0x64/0x88)
>  [<c03cd2d4>] (device_online) from [<c03cd360>] (online_store+0x68/0x74)
>  [<c03cd360>] (online_store) from [<c01b4ce0>] (kernfs_fop_write+0xb8/0x19c)
>  [<c01b4ce0>] (kernfs_fop_write) from [<c0144124>] (__vfs_write+0x20/0xd8)
>  [<c0144124>] (__vfs_write) from [<c01449c0>] (vfs_write+0x90/0x164)
>  [<c01449c0>] (vfs_write) from [<c01451e4>] (SyS_write+0x44/0x9c)
>  [<c01451e4>] (SyS_write) from [<c0010240>] (ret_fast_syscall+0x0/0x54)
>  CPU1: smp_ops.cpu_die() returned, trying to resuscitate
> 
> Cc: Tero Kristo <t-kristo@ti.com>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>

Applying into omap-for-v4.4/fixes thanks.

Tony

> ---
>  arch/arm/mach-omap2/omap-smp.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
> index 5305ec7..79e1f87 100644
> --- a/arch/arm/mach-omap2/omap-smp.c
> +++ b/arch/arm/mach-omap2/omap-smp.c
> @@ -143,9 +143,9 @@ static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
>  		 * Ensure that CPU power state is set to ON to avoid CPU
>  		 * powerdomain transition on wfi
>  		 */
> -		clkdm_wakeup(cpu1_clkdm);
> -		omap_set_pwrdm_state(cpu1_pwrdm, PWRDM_POWER_ON);
> -		clkdm_allow_idle(cpu1_clkdm);
> +		clkdm_wakeup_nolock(cpu1_clkdm);
> +		pwrdm_set_next_pwrst(cpu1_pwrdm, PWRDM_POWER_ON);
> +		clkdm_allow_idle_nolock(cpu1_clkdm);
>  
>  		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
>  			while (gic_dist_disabled()) {
> -- 
> 2.6.3
>
diff mbox

Patch

diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
index 5305ec7..79e1f87 100644
--- a/arch/arm/mach-omap2/omap-smp.c
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -143,9 +143,9 @@  static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
 		 * Ensure that CPU power state is set to ON to avoid CPU
 		 * powerdomain transition on wfi
 		 */
-		clkdm_wakeup(cpu1_clkdm);
-		omap_set_pwrdm_state(cpu1_pwrdm, PWRDM_POWER_ON);
-		clkdm_allow_idle(cpu1_clkdm);
+		clkdm_wakeup_nolock(cpu1_clkdm);
+		pwrdm_set_next_pwrst(cpu1_pwrdm, PWRDM_POWER_ON);
+		clkdm_allow_idle_nolock(cpu1_clkdm);
 
 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
 			while (gic_dist_disabled()) {