From d7737ce964d944dd07e25b0f569edcd550ede18c Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 26 Apr 2016 13:03:51 -0700 Subject: [PATCH] PM / runtime: Add _rcuidle suffix to allow rpm_idle() use from idle This commit appends a few _rcuidle suffixes to fix the following RCU-used-from-idle bug: > =============================== > [ INFO: suspicious RCU usage. ] > 4.6.0-rc5-next-20160426+ #1116 Not tainted > ------------------------------- > include/trace/events/rpm.h:95 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! > 1 lock held by swapper/0/0: > #0: (&(&dev->power.lock)->rlock){-.-...}, at: [] __rpm_callback+0x58/0x60 > > stack backtrace: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1116 > Hardware name: Generic OMAP36xx (Flattened Device Tree) > [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > [] (show_stack) from [] (dump_stack+0xb0/0xe4) > [] (dump_stack) from [] (rpm_suspend+0x580/0x768) > [] (rpm_suspend) from [] (__pm_runtime_suspend+0x64/0x84) > [] (__pm_runtime_suspend) from [] (omap2_gpio_prepare_for_idle+0x5c/0x70) > [] (omap2_gpio_prepare_for_idle) from [] (omap_sram_idle+0x140/0x244) > [] (omap_sram_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) In the immortal words of Steven Rostedt, "*Whack* *Whack* *Whack*!!!" Reported-by: Tony Lindgren Signed-off-by: Paul E. McKenney Tested-by: Tony Lindgren Tested-by: Guenter Roeck WhACKED-by: Steven Rostedt Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 76127e109ed2..17995fadebd7 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -301,7 +301,7 @@ static int rpm_idle(struct device *dev, int rpmflags) int (*callback)(struct device *); int retval; - trace_rpm_idle(dev, rpmflags); + trace_rpm_idle_rcuidle(dev, rpmflags); retval = rpm_check_suspend_allowed(dev); if (retval < 0) ; /* Conditions are wrong. */ @@ -337,7 +337,7 @@ static int rpm_idle(struct device *dev, int rpmflags) dev->power.request_pending = true; queue_work(pm_wq, &dev->power.work); } - trace_rpm_return_int(dev, _THIS_IP_, 0); + trace_rpm_return_int_rcuidle(dev, _THIS_IP_, 0); return 0; } @@ -352,7 +352,7 @@ static int rpm_idle(struct device *dev, int rpmflags) wake_up_all(&dev->power.wait_queue); out: - trace_rpm_return_int(dev, _THIS_IP_, retval); + trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval); return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO); } -- 2.30.2