From 918af9f941af9995fcaa7ef1eb67c433a492e2b3 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Mon, 16 Nov 2015 19:38:53 +0200 Subject: [PATCH] ARM: OMAP4+: SMP: use lockless clkdm/pwrdm api in omap4_boot_secondary 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: [] vfs_write+0x13c/0x164 #1: (&of->mutex){+.+.+.}, at: [] kernfs_fop_write+0x48/0x19c #2: (s_active#24){.+.+.+}, at: [] kernfs_fop_write+0x50/0x19c #3: (device_hotplug_lock){+.+.+.}, at: [] lock_device_hotplug_sysfs+0xc/0x4c #4: (&dev->mutex){......}, at: [] device_online+0x14/0x88 #5: (cpu_add_remove_lock){+.+.+.}, at: [] cpu_up+0x50/0x1a0 #6: (cpu_hotplug.lock){++++++}, at: [] cpu_hotplug_begin+0x0/0xc4 #7: (cpu_hotplug.lock#2){+.+.+.}, at: [] cpu_hotplug_begin+0x78/0xc4 #8: (boot_lock){+.+...}, at: [] 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) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0x80/0x94) [] (dump_stack) from [] (rt_spin_lock+0x24/0x54) [] (rt_spin_lock) from [] (clkdm_wakeup+0x10/0x2c) [] (clkdm_wakeup) from [] (omap4_boot_secondary+0x88/0x178) [] (omap4_boot_secondary) from [] (__cpu_up+0xc4/0x164) [] (__cpu_up) from [] (cpu_up+0x15c/0x1a0) [] (cpu_up) from [] (device_online+0x64/0x88) [] (device_online) from [] (online_store+0x68/0x74) [] (online_store) from [] (kernfs_fop_write+0xb8/0x19c) [] (kernfs_fop_write) from [] (__vfs_write+0x20/0xd8) [] (__vfs_write) from [] (vfs_write+0x90/0x164) [] (vfs_write) from [] (SyS_write+0x44/0x9c) [] (SyS_write) from [] (ret_fast_syscall+0x0/0x54) CPU1: smp_ops.cpu_die() returned, trying to resuscitate Cc: Tero Kristo Signed-off-by: Grygorii Strashko Signed-off-by: Tony Lindgren --- 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 5305ec7341ec..79e1f876d1c9 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()) {