Hi everyone, Anyone already noticed or started bisecting warnings coming from clk_core_disable_lock/exynos_pd_power on recent linux-next? On next-20180116, Odroid XU3 and HC1 (Exynso5422): [ 0.882736] EXYNOS5420 PMU initialized [ 0.891979] ------------[ cut here ]------------ [ 0.892220] WARNING: CPU: 0 PID: 59 at ../drivers/clk/clk.c:811 clk_core_disable_lock+0x18/0x24 [ 0.892383] Modules linked in: [ 0.892476] CPU: 0 PID: 59 Comm: kworker/0:1 Not tainted 4.15.0-rc8-next-20180116 #1121 [ 0.892629] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 0.892763] Workqueue: pm genpd_power_off_work_fn [ 0.892891] [<c0111f90>] (unwind_backtrace) from [<c010e360>] (show_stack+0x10/0x14) [ 0.893051] [<c010e360>] (show_stack) from [<c0a19860>] (dump_stack+0x98/0xc4) [ 0.893209] [<c0a19860>] (dump_stack) from [<c012662c>] (__warn+0xf8/0x110) [ 0.893353] [<c012662c>] (__warn) from [<c012675c>] (warn_slowpath_null+0x40/0x48) [ 0.893511] [<c012675c>] (warn_slowpath_null) from [<c04b9a98>] (clk_core_disable_lock+0x18/0x24) [ 0.893689] [<c04b9a98>] (clk_core_disable_lock) from [<c04ba820>] (clk_core_disable_unprepare+0xc/0x20) [ 0.893874] [<c04ba820>] (clk_core_disable_unprepare) from [<c04ba87c>] (__clk_set_parent_after+0x48/0x4c) [ 0.894063] [<c04ba87c>] (__clk_set_parent_after) from [<c04bb57c>] (clk_core_set_parent_nolock+0x27c/0x5e8) [ 0.894253] [<c04bb57c>] (clk_core_set_parent_nolock) from [<c04bb920>] (clk_set_parent+0x38/0x6c) [ 0.894438] [<c04bb920>] (clk_set_parent) from [<c04c9ea8>] (exynos_pd_power+0x88/0x1e4) [ 0.894603] [<c04c9ea8>] (exynos_pd_power) from [<c0587ed8>] (genpd_power_off+0x160/0x274) [ 0.894771] [<c0587ed8>] (genpd_power_off) from [<c0588a10>] (genpd_power_off_work_fn+0x2c/0x40) [ 0.894953] [<c0588a10>] (genpd_power_off_work_fn) from [<c01465b4>] (process_one_work+0x2d4/0x8f0) [ 0.895132] [<c01465b4>] (process_one_work) from [<c0147860>] (worker_thread+0x38/0x584) [ 0.895297] [<c0147860>] (worker_thread) from [<c014d794>] (kthread+0x138/0x168) [ 0.895450] [<c014d794>] (kthread) from [<c01010b4>] (ret_from_fork+0x14/0x20) Later there is also a lockdep warning but it looks like second issue: [ 5.932966] ====================================================== [ 5.937199] usb 5-1: new high-speed USB device number 2 using xhci-hcd [ 5.939073] WARNING: possible circular locking dependency detected [ 5.939110] 4.15.0-rc8-next-20180116 #1121 Tainted: G W [ 5.958143] ------------------------------------------------------ [ 5.964299] kworker/0:1/59 is trying to acquire lock: [ 5.969304] (&genpd->mlock){+.+.}, at: [<6abc3872>] genpd_runtime_resume+0x104/0x260 [ 5.977155] [ 5.977155] but task is already holding lock: [ 5.982926] (prepare_lock){+.+.}, at: [<74cef905>] clk_prepare_lock+0x10/0xf8 [ 5.990143] [ 5.990143] which lock already depends on the new lock. [ 5.990143] [ 5.998309] [ 5.998309] the existing dependency chain (in reverse order) is: [ 6.005739] [ 6.005739] -> #1 (prepare_lock){+.+.}: [ 6.011042] mutex_lock_nested+0x1c/0x24 [ 6.015419] clk_prepare_lock+0x50/0xf8 [ 6.019755] clk_unprepare+0x1c/0x2c [ 6.023841] exynos_pd_power+0x1a8/0x1e4 [ 6.028246] genpd_power_off+0x160/0x274 [ 6.032664] genpd_power_off_work_fn+0x2c/0x40 [ 6.037630] process_one_work+0x2d4/0x8f0 [ 6.042104] worker_thread+0x38/0x584 [ 6.046268] kthread+0x138/0x168 [ 6.049981] ret_from_fork+0x14/0x20 [ 6.054044] (null) [ 6.056794] [ 6.056794] -> #0 (&genpd->mlock){+.+.}: [ 6.062238] __mutex_lock+0x7c/0xa68 [ 6.066278] mutex_lock_nested+0x1c/0x24 [ 6.070703] genpd_runtime_resume+0x104/0x260 [ 6.075557] __rpm_callback+0xc0/0x21c [ 6.079792] rpm_callback+0x20/0x80 [ 6.083774] rpm_resume+0x558/0x7dc [ 6.087762] __pm_runtime_resume+0x60/0x98 [ 6.092367] clk_core_prepare+0x44/0x490 [ 6.096783] clk_prepare+0x20/0x30 [ 6.100674] amba_get_enable_pclk+0x2c/0x60 [ 6.105363] amba_device_try_add+0x8c/0x20c [ 6.110041] amba_deferred_retry_func+0x40/0xbc [ 6.115080] process_one_work+0x2d4/0x8f0 [ 6.119569] worker_thread+0x38/0x584 [ 6.123727] kthread+0x138/0x168 [ 6.127444] ret_from_fork+0x14/0x20 [ 6.131510] (null) [ 6.134263] [ 6.134263] other info that might help us debug this: [ 6.134263] [ 6.142328] Possible unsafe locking scenario: [ 6.142328] [ 6.148178] CPU0 CPU1 [ 6.152656] ---- ---- [ 6.157160] lock(prepare_lock); [ 6.160439] lock(&genpd->mlock); [ 6.166365] lock(prepare_lock); [ 6.172168] lock(&genpd->mlock); [ 6.175517] [ 6.175517] *** DEADLOCK *** [ 6.175517] [ 6.181475] 4 locks held by kworker/0:1/59: [ 6.185580] #0: ((wq_completion)"events"){+.+.}, at: [<f71c19aa>] process_one_work+0x210/0x8f0 [ 6.194407] #1: ((deferred_retry_work).work){+.+.}, at: [<f71c19aa>] process_one_work+0x210/0x8f0 [ 6.203422] #2: (deferred_devices_lock){+.+.}, at: [<3e940c1f>] amba_deferred_retry_func+0x1c/0xbc [ 6.212522] #3: (prepare_lock){+.+.}, at: [<74cef905>] clk_prepare_lock+0x10/0xf8 [ 6.220128] [ 6.220128] stack backtrace: [ 6.224438] CPU: 0 PID: 59 Comm: kworker/0:1 Tainted: G W 4.15.0-rc8-next-20180116 #1121 [ 6.233757] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 6.239791] Workqueue: events amba_deferred_retry_func [ 6.244929] [<c0111f90>] (unwind_backtrace) from [<c010e360>] (show_stack+0x10/0x14) [ 6.252670] [<c010e360>] (show_stack) from [<c0a19860>] (dump_stack+0x98/0xc4) [ 6.259877] [<c0a19860>] (dump_stack) from [<c0181478>] (print_circular_bug.constprop.17+0x210/0x32c) [ 6.269077] [<c0181478>] (print_circular_bug.constprop.17) from [<c01848f8>] (__lock_acquire+0x155c/0x1ac8) [ 6.278786] [<c01848f8>] (__lock_acquire) from [<c0185884>] (lock_acquire+0xe0/0x2bc) [ 6.286558] [<c0185884>] (lock_acquire) from [<c0a31788>] (__mutex_lock+0x7c/0xa68) [ 6.294181] [<c0a31788>] (__mutex_lock) from [<c0a32190>] (mutex_lock_nested+0x1c/0x24) [ 6.302161] [<c0a32190>] (mutex_lock_nested) from [<c05885dc>] (genpd_runtime_resume+0x104/0x260) [ 6.311008] [<c05885dc>] (genpd_runtime_resume) from [<c057c6c4>] (__rpm_callback+0xc0/0x21c) [ 6.319484] [<c057c6c4>] (__rpm_callback) from [<c057c840>] (rpm_callback+0x20/0x80) [ 6.327185] [<c057c840>] (rpm_callback) from [<c057c2a8>] (rpm_resume+0x558/0x7dc) [ 6.334721] [<c057c2a8>] (rpm_resume) from [<c057c58c>] (__pm_runtime_resume+0x60/0x98) [ 6.342706] [<c057c58c>] (__pm_runtime_resume) from [<c04b7f6c>] (clk_core_prepare+0x44/0x490) [ 6.351297] [<c04b7f6c>] (clk_core_prepare) from [<c04ba304>] (clk_prepare+0x20/0x30) [ 6.359081] [<c04ba304>] (clk_prepare) from [<c04b52f4>] (amba_get_enable_pclk+0x2c/0x60) [ 6.367229] [<c04b52f4>] (amba_get_enable_pclk) from [<c04b5510>] (amba_device_try_add+0x8c/0x20c) [ 6.376164] [<c04b5510>] (amba_device_try_add) from [<c04b56f8>] (amba_deferred_retry_func+0x40/0xbc) [ 6.385361] [<c04b56f8>] (amba_deferred_retry_func) from [<c01465b4>] (process_one_work+0x2d4/0x8f0) [ 6.394457] [<c01465b4>] (process_one_work) from [<c0147860>] (worker_thread+0x38/0x584) [ 6.402497] [<c0147860>] (worker_thread) from [<c014d794>] (kthread+0x138/0x168) [ 6.409852] [<c014d794>] (kthread) from [<c01010b4>] (ret_from_fork+0x14/0x20) Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html