From f17a0dd1c2e0d05c38589c9a13a36db455b74818 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 26 Apr 2016 14:02:23 -0700 Subject: [PATCH] clk: Use _rcuidle suffix to allow clk_core_enable() to used from idle This commit fixes the RCU use-from-idle bug corresponding the following splat: > [ INFO: suspicious RCU usage. ] > 4.6.0-rc5-next-20160426+ #1127 Not tainted > ------------------------------- > include/trace/events/clk.h:45 suspicious rcu_dereference_check() usage! > > other info that might help us debug this: > > > RCU used illegally from idle CPU! > rcu_scheduler_active = 1, debug_locks = 0 > RCU used illegally from extended quiescent state! > 2 locks held by swapper/0/0: > #0: (&oh->hwmod_key#30){......}, at: [] omap_hwmod_enable+0x18/0x44 > #1: (enable_lock){......}, at: [] clk_enable_lock+0x18/0x124 > > stack backtrace: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1127 > Hardware name: Generic OMAP36xx (Flattened Device Tree) > [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > [] (show_stack) from [] (dump_stack+0xb0/0xe4) > [] (dump_stack) from [] (clk_core_enable+0x1e0/0x36c) > [] (clk_core_enable) from [] (clk_enable+0x1c/0x38) > [] (clk_enable) from [] (_enable_clocks+0x18/0x7c) > [] (_enable_clocks) from [] (_enable+0x114/0x2ec) > [] (_enable) from [] (omap_hwmod_enable+0x24/0x44) > [] (omap_hwmod_enable) from [] (omap_device_enable+0x3c/0x90) > [] (omap_device_enable) from [] (_od_runtime_resume+0x10/0x38) > [] (_od_runtime_resume) from [] (__rpm_callback+0x2c/0x60) > [] (__rpm_callback) from [] (rpm_callback+0x20/0x80) > [] (rpm_callback) from [] (rpm_resume+0x3d0/0x6f0) > [] (rpm_resume) from [] (__pm_runtime_resume+0x4c/0x64) > [] (__pm_runtime_resume) from [] (omap2_gpio_resume_after_idle+0x54/0x68) > [] (omap2_gpio_resume_after_idle) from [] (omap3_enter_idle_bm+0xfc/0x1ec) > [] (omap3_enter_idle_bm) from [] (cpuidle_enter_state+0x80/0x3d4) > [] (cpuidle_enter_state) from [] (cpu_startup_entry+0x198/0x3a0) > [] (cpu_startup_entry) from [] (start_kernel+0x354/0x3c8) > [] (start_kernel) from [<8000807c>] (0x8000807c) Reported-by: Tony Lindgren Signed-off-by: Paul E. McKenney Tested-by: Tony Lindgren Tested-by: Guenter Roeck Cc: Russell King Cc: Steven Rostedt Cc: Michael Turquette Cc: Stephen Boyd Cc: Cc: Cc: --- drivers/clk/clk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 4fa43c02d682..ec83f404c1d2 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -735,12 +735,12 @@ static int clk_core_enable(struct clk_core *core) if (ret) return ret; - trace_clk_enable(core); + trace_clk_enable_rcuidle(core); if (core->ops->enable) ret = core->ops->enable(core->hw); - trace_clk_enable_complete(core); + trace_clk_enable_complete_rcuidle(core); if (ret) { clk_core_disable(core->parent); -- 2.20.1