On 13/06/2019 10:20, Pi-Hsun Shih wrote: > (Sorry for the possibly double-posting, my last mail got rejected by > some mailing lists.) > > Hi, > When I tested this patch series (Based on linux 5.2.0-rc2, and with > various other patch series about MT8183) with lockdep enabled, and I'm > seeing the following lockdep warning on boot. > > By bisecting the commits, the first commit that introduce this warning > is this patch. The warning also doesn't appear if Are you sure about this? >From the lockdep call graph it looks more like patch [PATCH v7 15/21] memory: mtk-smi: Invoke pm runtime_callback to enable clocks has something to do with it. But not an expert either, sorry. Regards, Matthias > https://lore.kernel.org/patchwork/patch/1086582/ and > https://lore.kernel.org/patchwork/patch/1086583/ are not applied. > > Do anyone have idea on why this is happening, or any suggestion on > which part I should be digging into to figure this out? Thanks. > > [ 4.664194] ====================================================== > [ 4.670368] WARNING: possible circular locking dependency detected > [ 4.676545] 5.2.0-rc2-next-20190528-44527-g6c94b6475c04 #20 Tainted: G S > [ 4.684539] ------------------------------------------------------ > [ 4.690714] kworker/4:1/51 is trying to acquire lock: > [ 4.695760] (____ptrval____) (regulator_list_mutex){+.+.}, > at:regulator_lock_dependent+0xdc/0x6c4 > [ 4.704732] > [ 4.704732] but task is already holding lock: > [ 4.710556] (____ptrval____) (&genpd->mlock/1){+.+.}, > at:genpd_lock_nested_mtx+0x24/0x30 > [ 4.718740] > [ 4.718740] which lock already depends on the new lock. > [ 4.718740] > [ 4.726908] > [ 4.726908] the existing dependency chain (in reverse order) is: > [ 4.734382] > [ 4.734382] -> #4 (&genpd->mlock/1){+.+.}: > [ 4.739963] __mutex_lock_common+0x1a0/0x1fe8 > [ 4.744836] mutex_lock_nested+0x40/0x50 > [ 4.749275] genpd_lock_nested_mtx+0x24/0x30 > [ 4.754063] genpd_add_subdomain+0x150/0x524 > [ 4.758850] pm_genpd_add_subdomain+0x3c/0x5c > [ 4.763723] scpsys_probe+0x520/0xe78 > [ 4.767902] platform_drv_probe+0xf4/0x134 > [ 4.772517] really_probe+0x214/0x4dc > [ 4.776696] driver_probe_device+0xcc/0x1d4 > [ 4.781396] __device_attach_driver+0x10c/0x180 > [ 4.786442] bus_for_each_drv+0x124/0x184 > [ 4.790968] __device_attach+0x1c0/0x2d8 > [ 4.795407] device_initial_probe+0x20/0x2c > [ 4.800106] bus_probe_device+0x80/0x16c > [ 4.804546] deferred_probe_work_func+0x120/0x168 > [ 4.809767] process_one_work+0x858/0x1208 > [ 4.814379] worker_thread+0x9ec/0xcb8 > [ 4.818644] kthread+0x2b8/0x2d0 > [ 4.822391] ret_from_fork+0x10/0x18 > [ 4.826480] > [ 4.826480] -> #3 (&genpd->mlock){+.+.}: > [ 4.831880] __mutex_lock_common+0x1a0/0x1fe8 > [ 4.836752] mutex_lock_nested+0x40/0x50 > [ 4.841190] genpd_lock_mtx+0x20/0x2c > [ 4.845369] genpd_runtime_resume+0x140/0x434 > [ 4.850241] __rpm_callback+0xb0/0x1e4 > [ 4.854506] rpm_callback+0x54/0x1a8 > [ 4.858597] rpm_resume+0xc6c/0x10c4 > [ 4.862689] __pm_runtime_resume+0xb4/0x124 > [ 4.867387] device_link_add+0x598/0x8d0 > [ 4.871829] mtk_smi_larb_probe+0x2b0/0x340 > [ 4.876528] platform_drv_probe+0xf4/0x134 > [ 4.881141] really_probe+0x214/0x4dc > [ 4.885320] driver_probe_device+0xcc/0x1d4 > [ 4.890020] __device_attach_driver+0x10c/0x180 > [ 4.895066] bus_for_each_drv+0x124/0x184 > [ 4.899591] __device_attach+0x1c0/0x2d8 > [ 4.904031] device_initial_probe+0x20/0x2c > [ 4.908730] bus_probe_device+0x80/0x16c > [ 4.913169] deferred_probe_work_func+0x120/0x168 > [ 4.918387] process_one_work+0x858/0x1208 > [ 4.923000] worker_thread+0x9ec/0xcb8 > [ 4.927264] kthread+0x2b8/0x2d0 > [ 4.931009] ret_from_fork+0x10/0x18 > [ 4.935098] > [ 4.935098] -> #2 (dpm_list_mtx){+.+.}: > [ 4.940412] __mutex_lock_common+0x1a0/0x1fe8 > [ 4.945284] mutex_lock_nested+0x40/0x50 > [ 4.949722] device_pm_lock+0x1c/0x24 > [ 4.953900] device_link_add+0x98/0x8d0 > [ 4.958252] _regulator_get+0x3f0/0x504 > [ 4.962606] _devm_regulator_get+0x58/0xb8 > [ 4.967218] devm_regulator_get+0x28/0x34 > [ 4.971746] pwm_backlight_probe+0x61c/0x1b90 > [ 4.976617] platform_drv_probe+0xf4/0x134 > [ 4.981230] really_probe+0x214/0x4dc > [ 4.985409] driver_probe_device+0xcc/0x1d4 > [ 4.990108] device_driver_attach+0xe4/0x104 > [ 4.994894] __driver_attach+0x134/0x14c > [ 4.999333] bus_for_each_dev+0x120/0x180 > [ 5.003859] driver_attach+0x48/0x54 > [ 5.007950] bus_add_driver+0x2ac/0x44c > [ 5.012303] driver_register+0x160/0x288 > [ 5.016742] __platform_driver_register+0xcc/0xdc > [ 5.021964] pwm_backlight_driver_init+0x1c/0x24 > [ 5.027097] do_one_initcall+0x38c/0x994 > [ 5.031536] do_initcall_level+0x3a4/0x4b8 > [ 5.036148] do_basic_setup+0x84/0xa0 > [ 5.036153] kernel_init_freeable+0x23c/0x324 > [ 5.036158] kernel_init+0x14/0x110 > [ 5.036164] ret_from_fork+0x10/0x18 > [ 5.036166] > [ 5.036166] -> #1 (device_links_lock){+.+.}: > [ 5.065905] __mutex_lock_common+0x1a0/0x1fe8 > [ 5.070777] mutex_lock_nested+0x40/0x50 > [ 5.075215] device_link_remove+0x40/0xe0 > [ 5.079740] _regulator_put+0x104/0x2d8 > [ 5.084093] regulator_put+0x30/0x44 > [ 5.088184] devm_regulator_release+0x38/0x44 > [ 5.093056] release_nodes+0x604/0x670 > [ 5.097320] devres_release_all+0x70/0x8c > [ 5.101846] really_probe+0x270/0x4dc > [ 5.106024] driver_probe_device+0xcc/0x1d4 > [ 5.110724] device_driver_attach+0xe4/0x104 > [ 5.115510] __driver_attach+0x134/0x14c > [ 5.119949] bus_for_each_dev+0x120/0x180 > [ 5.124474] driver_attach+0x48/0x54 > [ 5.128566] bus_add_driver+0x2ac/0x44c > [ 5.132919] driver_register+0x160/0x288 > [ 5.137357] __platform_driver_register+0xcc/0xdc > [ 5.142576] pwm_backlight_driver_init+0x1c/0x24 > [ 5.147708] do_one_initcall+0x38c/0x994 > [ 5.152146] do_initcall_level+0x3a4/0x4b8 > [ 5.156758] do_basic_setup+0x84/0xa0 > [ 5.160936] kernel_init_freeable+0x23c/0x324 > [ 5.165807] kernel_init+0x14/0x110 > [ 5.169813] ret_from_fork+0x10/0x18 > [ 5.173901] > [ 5.173901] -> #0 (regulator_list_mutex){+.+.}: > [ 5.179910] lock_acquire+0x350/0x4d4 > [ 5.184088] __mutex_lock_common+0x1a0/0x1fe8 > [ 5.184095] mutex_lock_nested+0x40/0x50 > [ 5.197475] regulator_lock_dependent+0xdc/0x6c4 > [ 5.197482] regulator_disable+0xa0/0x138 > [ 5.197487] scpsys_power_off+0x38c/0x4bc > [ 5.197495] genpd_power_off+0x3d8/0x6a0 > [ 5.209399] genpd_power_off+0x530/0x6a0 > [ 5.209406] genpd_power_off_work_fn+0x74/0xc0 > [ 5.209411] process_one_work+0x858/0x1208 > [ 5.209419] worker_thread+0x9ec/0xcb8 > [ 5.219067] kthread+0x2b8/0x2d0 > [ 5.219073] ret_from_fork+0x10/0x18 > [ 5.219077] > [ 5.219077] other info that might help us debug this: > [ 5.219077] > [ 5.219080] Chain exists of: > [ 5.219080] regulator_list_mutex --> &genpd->mlock --> &genpd->mlock/1 > [ 5.219080] > [ 5.228039] Possible unsafe locking scenario: > [ 5.228039] > [ 5.228042] CPU0 CPU1 > [ 5.228046] ---- ---- > [ 5.228048] lock(&genpd->mlock/1); > [ 5.228058] lock(&genpd->mlock); > [ 5.311647] lock(&genpd->mlock/1); > [ 5.317736] lock(regulator_list_mutex); > [ 5.321742] > [ 5.321742] *** DEADLOCK *** > [ 5.321742] > [ 5.327655] 4 locks held by kworker/4:1/51: > [ 5.331831] #0: (____ptrval____) ((wq_completion)pm){+.+.}, > at:process_one_work+0x57c/0x1208 > [ 5.340444] #1: (____ptrval____) > ((work_completion)(&genpd->power_off_work)){+.+.}, > at:process_one_work+0x5b8/0x1208 > [ 5.351139] #2: (____ptrval____) (&genpd->mlock){+.+.}, > at:genpd_lock_mtx+0x20/0x2c > [ 5.358970] #3: (____ptrval____) (&genpd->mlock/1){+.+.}, > at:genpd_lock_nested_mtx+0x24/0x30 > [ 5.367584] > [ 5.367584] stack backtrace: > [ 5.371939] CPU: 4 PID: 51 Comm: kworker/4:1 Tainted: G S > 5.2.0-rc2-next-20190528-44527-g6c94b6475c04 #20 > [ 5.382809] Workqueue: pm genpd_power_off_work_fn > [ 5.382816] Call trace: > [ 5.382822] dump_backtrace+0x0/0x2c0 > [ 5.382830] show_stack+0x20/0x2c > [ 5.409174] dump_stack+0x10c/0x17c > [ 5.412659] print_circular_bug+0x42c/0x4d0 > [ 5.416838] __lock_acquire+0x4c88/0x5484 > [ 5.420843] lock_acquire+0x350/0x4d4 > [ 5.424500] __mutex_lock_common+0x1a0/0x1fe8 > [ 5.428851] mutex_lock_nested+0x40/0x50 > [ 5.432770] regulator_lock_dependent+0xdc/0x6c4 > [ 5.437383] regulator_disable+0xa0/0x138 > [ 5.441389] scpsys_power_off+0x38c/0x4bc > [ 5.445393] genpd_power_off+0x3d8/0x6a0 > [ 5.449310] genpd_power_off+0x530/0x6a0 > [ 5.453229] genpd_power_off_work_fn+0x74/0xc0 > [ 5.457667] process_one_work+0x858/0x1208 > [ 5.461758] worker_thread+0x9ec/0xcb8 > [ 5.465503] kthread+0x2b8/0x2d0 > [ 5.468727] ret_from_fork+0x10/0x18 > > On Mon, Jun 10, 2019 at 8:21 PM Yong Wu <yong.wu@xxxxxxxxxxxx> wrote: >> ... >> + } else { >> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> + common->base = devm_ioremap_resource(dev, res); >> + if (IS_ERR(common->base)) >> + return PTR_ERR(common->base); >> } >> pm_runtime_enable(dev); >> platform_set_drvdata(pdev, common);
