On Thu, Aug 26, 2021 at 1:22 AM Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote: > > > >>> Btw, I've been working on [1] cleaning up the one-off deferred probe > >>> solution that we have for amba devices. That causes a bunch of other > >>> headaches. Your patch 3/3 takes us further in the wrong direction by > >>> adding more reasons for delaying the addition of the device. > > Hi Saravana, I try the link[1], but with it, there is a crash when boot > (qemu-system-arm -M vexpress-a15), Hi, It's hard to make sense of the logs. Looks like two different threads might be printing to the log at the same time? Can you please enable the config that prints the thread ID (forgot what it's called) and collect this again? With what I could tell the crash seems to be happening somewhere in platform_match(), but that's not related to this patch at all? -Saravana > > without it, boot successfully. > > [ 2.246057] aaci-pl041 1c040000.aaci: ARM AC'97 Interface PL041 rev0 > at 0x1c040000, irq 36 > [ 2.246357] aaci-pl041 1c040000.aaci: FIFO 512 entries > [ 2.248617] NET: Registered PF_PACKET protocol family > [ 2.250481] 9pnet: Installing 9P2000 support > [ 2.251474] Registering SWP/SWPB emulation handler > [ 2.284374] 1c090000.serial: ttyAMA0 at MMIO 0x1c090000 (irq = 41, > base_baud = 0) is a PL011 rev1 > [ 2.287797] printk: console [ttyAMA0] enabled > [ 2.287797] printk: console [ttyAMA0] enabled > [ 2.288262] input: AT Raw Set 2 keyboard as > /devices/platform/bus@8000000/bus@8000000:motherboard-bus/bus@8000000:motherboard-bus:iofpga-bus@300000000/1c060000.kmi/serio0/input/input0 > [ 2.288262] input: AT Raw Set 2 keyboard as > /devices/platform/bus@8000000/bus@8000000:motherboard-bus/bus@8000000:motherboard-bus:iofpga-bus@300000000/1c060000.kmi/serio0/input/input0 > [ 2.288755] printk: bootconsole [earlycon0] disabled > [ 2.288755] printk: bootconsole [earlycon0] disabled > [ 2.294507] 1c0a0000.serial: ttyAMA1 at MMIO 0x1c0a0000 (irq = 42, > base_baud = 0) is a PL011 rev1 > [ 2.296950] 1c0b0000.serial: ttyAMA2 at MMIO 0x1c0b0000 (irq = 43, > base_baud = 0) is a PL011 rev1 > [ 2.298636] 1c0c0000.serial: ttyAMA3 at MMIO 0x1c0c0000 (irq = 44, > base_baud = 0) is a PL011 rev1 > [ 2.300496] 8<--- cut here --- > [ 2.300775] ------------[ cut here ]------------ > [ 2.301260] Unable to handle kernel NULL pointer dereference at > virtual address 00000000 > [ 2.300928] WARNING: CPU: 1 PID: 27 at > /home/wkf/work/hulk/lib/refcount.c:25 refcount_warn_saturate+0x108/0x174 > [ 2.301700] pgd = (ptrval) > [ 2.302002] refcount_t: addition on 0; use-after-free. > [ 2.302184] [00000000] *pgd=00000000 > [ 2.302363] Modules linked in: > [ 2.302384] > [ 2.302753] > [ 2.303501] CPU: 1 PID: 27 Comm: kworker/u4:1 Not tainted 5.14.0-rc7+ > #193 > [ 2.303990] Hardware name: ARM-Versatile Express > [ 2.304198] Internal error: Oops: 5 [#1] SMP ARM > [ 2.304537] Workqueue: events_unbound deferred_probe_work_func > [ 2.304829] Modules linked in: > [ 2.304865] > [ 2.305133] > [ 2.305401] Backtrace: > [ 2.305562] CPU: 0 PID: 41 Comm: kworker/0:2 Not tainted 5.14.0-rc7+ #193 > [ 2.305614] Hardware name: ARM-Versatile Express > [ 2.305576] > [ 2.305781] [<c010c780>] (dump_backtrace) from [<c010cacc>] > (show_stack+0x20/0x24) > [ 2.306266] Workqueue: events_long serio_handle_event > [ 2.306732] r7:00000009 r6:00000000 r5:c0b1efb8 r4:600b0093 > [ 2.306889] PC is at strcmp+0x18/0x44 > [ 2.307115] [<c010caac>] (show_stack) from [<c091eba4>] > (dump_stack_lvl+0x48/0x54) > [ 2.307263] LR is at platform_match+0xb8/0xcc > [ 2.307498] [<c091eb5c>] (dump_stack_lvl) from [<c091ebc8>] > (dump_stack+0x18/0x1c) > [ 2.307739] pc : [<c0560aec>] lr : [<c064626c>] psr: 60000013 > [ 2.307988] r5:c0b4ef98 r4:c165ddc4 > [ 2.308317] sp : c1675d70 ip : c1675d80 fp : c1675d7c > [ 2.308433] [<c091ebb0>] (dump_stack) from [<c01289c4>] > (__warn+0x110/0x114) > [ 2.308743] r10: 00000000 r9 : 00000000 r8 : 00000001 > [ 2.308961] [<c01288b4>] (__warn) from [<c0128a4c>] > (warn_slowpath_fmt+0x84/0xc0) > [ 2.309252] r7 : c0d04d08 r6 : c13aed18 r5 : c1090fc0 r4 : c13aed18 > [ 2.309547] r9:00000009 r8:c0504f10 r7:00000019 r6:c0b4ef98 > r5:c0b4efbc r4:c0d04d08 > [ 2.309975] [<c01289cc>] (warn_slowpath_fmt) from [<c0504f10>] > (refcount_warn_saturate+0x108/0x174) > [ 2.310531] r3 : c0a5e1c0 r2 : 00000002 r1 : c0b82860 r0 : 00000000 > [ 2.311263] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM > Segment none > [ 2.311298] r9:600b0013 r8:00000000 r7:00000000 r6:c1787eb8 > r5:c165de3c r4:c1702b38 > [ 2.311899] Control: 10c5387d Table: 8000406a DAC: 00000051 > [ 2.312117] [<c0504e08>] (refcount_warn_saturate) from [<c055657c>] > (klist_next+0x134/0x138) > [ 2.312755] Register r0 information: > [ 2.312964] [<c0556448>] (klist_next) from [<c06411dc>] > (bus_for_each_drv+0x74/0xc8) > [ 2.313345] NULL pointer > [ 2.313690] Register r1 information: > [ 2.313736] r9:00000000 r8:00000001 r7:c0d04d08 r6:c064373c > r5:c165de6c r4:00000000 > [ 2.313933] non-slab/vmalloc memory > [ 2.314172] [<c0641168>] (bus_for_each_drv) from [<c0642f38>] > (__device_attach+0xf0/0x15c) > [ 2.315042] r7:c10846b8 r6:c13ae444 r5:c13ae400 r4:c0d04d08 > [ 2.315060] Register r2 information: > [ 2.315243] [<c0642e48>] (__device_attach) from [<c064390c>] > (device_initial_probe+0x1c/0x20) > [ 2.315276] non-paged memory > [ 2.315569] r8:00000000 r7:c10846b8 r6:c13ae400 r5:c107d690 r4:c13ae400 > [ 2.315593] [<c06438f0>] (device_initial_probe) from [<c0642080>] > (bus_probe_device+0x94/0x9c) > [ 2.316192] [<c0641fec>] (bus_probe_device) from [<c064259c>] > (deferred_probe_work_func+0x8c/0xb8) > [ 2.316939] r7:c10846b8 r6:c10846a4 r5:c10846a4 r4:c13ae400 > [ 2.317573] [<c0642510>] (deferred_probe_work_func) from [<c01475a4>] > (process_one_work+0x238/0x594) > [ 2.318513] r9:00000000 r8:00000000 r7:c1225b00 r6:c1206200 > r5:c16b6f80 r4:c10846d4 > [ 2.318931] Register r3 information: non-slab/vmalloc memory > [ 2.319218] [<c014736c>] (process_one_work) from [<c0147bc4>] > (worker_thread+0x2c4/0x5f4) > [ 2.320001] r10:c0d03d00 r9:00000088 r8:ffffe000 r7:c1206218 > r6:c16b6f94 r5:c1206200 > [ 2.320280] Register r4 information: > [ 2.320614] r4:c16b6f80 > [ 2.320942] [<c0147900>] (worker_thread) from [<c014feb4>] > (kthread+0x178/0x194) > [ 2.321111] slab kmalloc-1k > [ 2.321403] r10:c165c000 r9:c1313e74 r8:00000000 r7:c16b6f80 > r6:c0147900 r5:c16b5580 > [ 2.321391] start c13aec00 pointer offset 280 > [ 2.321993] r4:c13d4980 > [ 2.322006] size 1024 > [ 2.322176] [<c014fd3c>] (kthread) from [<c0100150>] > (ret_from_fork+0x14/0x24) > [ 2.323165] Exception stack(0xc165dfb0 to 0xc165dff8) > [ 2.323187] > [ 2.323371] Register r5 information: non-slab/vmalloc memory > [ 2.323535] Register r6 information: slab kmalloc-1k start c13aec00 > pointer offset 280 size 1024 > [ 2.324594] Register r7 information: > [ 2.324597] dfa0: 00000000 > 00000000 00000000 00000000 > [ 2.325507] non-slab/vmalloc memory > [ 2.325830] Register r8 information: non-paged memory > [ 2.326267] Register r9 information: > [ 2.326274] dfc0: 00000000 00000000 00000000 00000000 00000000 > 00000000 00000000 00000000 > [ 2.326453] NULL pointer > [ 2.326942] Register r10 information: NULL pointer > [ 2.327159] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 > [ 2.327258] Register r11 information: non-slab/vmalloc memory > [ 2.327904] Register r12 information: > [ 2.327928] r10:00000000 r9:00000000 r8:00000000 r7:00000000 > r6:00000000 r5:c014fd3c > [ 2.327937] non-slab/vmalloc memory > [ 2.328057] Process kworker/0:2 (pid: 41, stack limit = 0x(ptrval)) > [ 2.328204] Stack: (0xc1675d70 to 0xc1676000) > [ 2.328479] r4:c16b5580 > [ 2.329851] ---[ end trace f293b13f591ee203 ]--- > [ 2.330027] 5d60: c1675d9c > c1675d80 c064626c c0560ae0 > [ 2.331070] 5d80: c1090fc0 c1675df4 c13aed18 c0d04d08 c1675dbc > c1675da0 c0643778 c06461c0 > [ 2.331120] 8<--- cut here --- > [ 2.331739] Unhandled fault: page domain fault (0x01b) at 0x00000010 > [ 2.331915] 5da0: 00000000 c1675df4 c064373c c0d04d08 c1675dec > c1675dc0 c06411d0 c0643748 > [ 2.332379] pgd = (ptrval) > [ 2.332408] 5dc0: c1675dec c16bf06c c1787eb8 76076098 c0d04d08 > c13aed18 c13aed5c c13aa800 > [ 2.332889] [00000010] *pgd=00000000 > [ 2.332951] 5de0: c1675e24 c1675df0 c0642f38 c0641174 c1675e44 > c13aed18 00000001 76076098 > [ 2.333535] 5e00: 00000000 c13aed18 c108ea84 c13aed18 c13aa800 > c10843a0 c1675e34 c1675e28 > [ 2.334201] 5e20: c064390c c0642e54 c1675e54 c1675e38 c0642080 > c06438fc c13aed18 00000000 > [ 2.334845] 5e40: c0d04d08 c13aa800 c1675eb4 c1675e58 c063fa1c > c0641ff8 c13a5180 c1706380 > [ 2.335464] 5e60: eee2e0c0 c1201180 c071c008 c11ea558 c0b7f260 > c0b7f28c c1675eb4 c1675e88 > [ 2.336088] 5e80: c02e6368 76076098 00000001 c1706f4c c13aec00 > c108ea54 c1706f40 c11ea558 > [ 2.336758] 5ea0: c0b7f260 c0b7f28c c1675ef4 c1675eb8 c071c0e4 > c063f620 c0923300 c0158300 > [ 2.337399] 5ec0: 00000000 c13aed18 c1675ef4 c108ea70 c1702e80 > effc4400 effc7700 00000000 > [ 2.338025] 5ee0: 00000000 c10b2580 c1675f34 c1675ef8 c01475a4 > c071bf38 c13a5100 ffffe000 > [ 2.338663] 5f00: c1675f1c c1675f10 c0149250 c1702e80 effc4400 > c1702e94 effc4418 ffffe000 > [ 2.339296] 5f20: 00000008 c0d03d00 c1675f74 c1675f38 c014795c > c0147378 c130fe74 c0b0c2c4 > [ 2.340102] 5f40: c10b1d2a effc4400 c1675f74 c1706000 c1706880 > c0147900 c1702e80 00000000 > [ 2.340736] 5f60: c130fe74 c1674000 c1675fac c1675f78 c014feb4 > c014790c c1706024 c1706024 > [ 2.341315] 5f80: c1675fac c1706880 c014fd3c 00000000 00000000 > 00000000 00000000 00000000 > [ 2.341852] 5fa0: 00000000 c1675fb0 c0100150 c014fd48 00000000 > 00000000 00000000 00000000 > [ 2.342407] 5fc0: 00000000 00000000 00000000 00000000 00000000 > 00000000 00000000 00000000 > [ 2.342957] 5fe0: 00000000 00000000 00000000 00000000 00000013 > 00000000 00000000 00000000 > [ 2.343361] Backtrace: > [ 2.343573] [<c0560ad4>] (strcmp) from [<c064626c>] > (platform_match+0xb8/0xcc) > [ 2.343954] [<c06461b4>] (platform_match) from [<c0643778>] > (__device_attach_driver+0x3c/0xc4) > [ 2.344369] r7:c0d04d08 r6:c13aed18 r5:c1675df4 r4:c1090fc0 > [ 2.344615] [<c064373c>] (__device_attach_driver) from [<c06411d0>] > (bus_for_each_drv+0x68/0xc8) > [ 2.345015] r7:c0d04d08 r6:c064373c r5:c1675df4 r4:00000000 > [ 2.345283] [<c0641168>] (bus_for_each_drv) from [<c0642f38>] > (__device_attach+0xf0/0x15c) > [ 2.345654] r7:c13aa800 r6:c13aed5c r5:c13aed18 r4:c0d04d08 > [ 2.345903] [<c0642e48>] (__device_attach) from [<c064390c>] > (device_initial_probe+0x1c/0x20) > [ 2.346325] r8:c10843a0 r7:c13aa800 r6:c13aed18 r5:c108ea84 r4:c13aed18 > [ 2.346635] [<c06438f0>] (device_initial_probe) from [<c0642080>] > (bus_probe_device+0x94/0x9c) > [ 2.347038] [<c0641fec>] (bus_probe_device) from [<c063fa1c>] > (device_add+0x408/0x8b8) > [ 2.347419] r7:c13aa800 r6:c0d04d08 r5:00000000 r4:c13aed18 > [ 2.347695] [<c063f614>] (device_add) from [<c071c0e4>] > (serio_handle_event+0x1b8/0x234) > [ 2.348094] r10:c0b7f28c r9:c0b7f260 r8:c11ea558 r7:c1706f40 > r6:c108ea54 r5:c13aec00 > [ 2.348453] r4:c1706f4c > [ 2.348604] [<c071bf2c>] (serio_handle_event) from [<c01475a4>] > (process_one_work+0x238/0x594) > [ 2.348968] r10:c10b2580 r9:00000000 r8:00000000 r7:effc7700 > r6:effc4400 r5:c1702e80 > [ 2.349315] r4:c108ea70 > [ 2.349468] [<c014736c>] (process_one_work) from [<c014795c>] > (worker_thread+0x5c/0x5f4) > [ 2.349875] r10:c0d03d00 r9:00000008 r8:ffffe000 r7:effc4418 > r6:c1702e94 r5:effc4400 > [ 2.350169] r4:c1702e80 > [ 2.350315] [<c0147900>] (worker_thread) from [<c014feb4>] > (kthread+0x178/0x194) > [ 2.350687] r10:c1674000 r9:c130fe74 r8:00000000 r7:c1702e80 > r6:c0147900 r5:c1706880 > [ 2.351038] r4:c1706000 > [ 2.351182] [<c014fd3c>] (kthread) from [<c0100150>] > (ret_from_fork+0x14/0x24) > [ 2.351500] Exception stack(0xc1675fb0 to 0xc1675ff8) > [ 2.351855] 5fa0: 00000000 > 00000000 00000000 00000000 > [ 2.352415] 5fc0: 00000000 00000000 00000000 00000000 00000000 > 00000000 00000000 00000000 > [ 2.352923] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 > [ 2.353283] r10:00000000 r9:00000000 r8:00000000 r7:00000000 > r6:00000000 r5:c014fd3c > [ 2.353618] r4:c1706880 > [ 2.354146] Code: e24cb004 ea000001 e3530000 0a000006 (e4d03001) > [ 2.354860] Internal error: : 1b [#2] SMP ARM > [ 2.355172] Modules linked in: > [ 2.355254] ---[ end trace f293b13f591ee204 ]--- > [ 2.355650] CPU: 1 PID: 27 Comm: kworker/u4:1 Tainted: G D > W 5.14.0-rc7+ #193 > [ 2.355888] Kernel panic - not syncing: Fatal exception > [ 2.355990] Hardware name: ARM-Versatile Express > [ 2.356735] Workqueue: events_unbound deferred_probe_work_func > [ 2.357217] PC is at klist_put+0x20/0xa4 > [ 2.357537] LR is at klist_iter_exit+0x24/0x30 > [ 2.357872] pc : [<c0556280>] lr : [<c0556340>] psr: a00b0013 > [ 2.358299] sp : c165de00 ip : c165de20 fp : c165de1c > [ 2.358655] r10: c10b2580 r9 : 00000000 r8 : 00000001 > [ 2.359009] r7 : c1702b38 r6 : 00000000 r5 : c165de6c r4 : 00000000 > [ 2.359440] r3 : 00000000 r2 : 76076098 r1 : 00000000 r0 : 00000000 > [ 2.359893] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM > Segment none > [ 2.360368] Control: 10c5387d Table: 8177806a DAC: 00000051 > [ 2.360759] Register r0 information: NULL pointer > [ 2.361126] Register r1 information: NULL pointer > [ 2.361477] Register r2 information: non-paged memory > [ 2.361835] Register r3 information: NULL pointer > [ 2.362162] Register r4 information: NULL pointer > [ 2.362486] Register r5 information: non-slab/vmalloc memory > [ 2.362887] Register r6 information: NULL pointer > [ 2.363226] Register r7 information: slab kmalloc-128 start c1702b00 > pointer offset 56 size 128 > [ 2.363919] Register r8 information: non-paged memory > [ 2.364299] Register r9 information: NULL pointer > [ 2.364668] Register r10 information: non-slab/vmalloc memory > [ 2.365089] Register r11 information: non-slab/vmalloc memory > [ 2.365466] Register r12 information: non-slab/vmalloc memory > [ 2.365872] Process kworker/u4:1 (pid: 27, stack limit = 0x(ptrval)) > [ 2.366297] Stack: (0xc165de00 to 0xc165e000) > [ 2.366769] de00: c165de3c c165de6c c064373c c0d04d08 c165de34 > c165de20 c0556340 c055626c > [ 2.367478] de20: 00000000 c165de6c c165de64 c165de38 c0641208 > c0556328 c165de64 c136996c > [ 2.368192] de40: c1702b38 76076098 c0d04d08 c13ae400 c13ae444 > c10846b8 c165de9c c165de68 > [ 2.368934] de60: c0642f38 c0641174 c063c4c4 c13ae400 00000001 > 76076098 00000000 c13ae400 > [ 2.369654] de80: c107d690 c13ae400 c10846b8 00000000 c165deac > c165dea0 c064390c c0642e54 > [ 2.370367] dea0: c165decc c165deb0 c0642080 c06438fc c13ae400 > c10846a4 c10846a4 c10846b8 > [ 2.371046] dec0: c165def4 c165ded0 c064259c c0641ff8 c10846d4 > c16b6f80 c1206200 c1225b00 > [ 2.371774] dee0: 00000000 00000000 c165df34 c165def8 c01475a4 > c064251c c13906c0 ffffe000 > [ 2.372470] df00: c165df1c c165df10 c0149250 c16b6f80 c1206200 > c16b6f94 c1206218 ffffe000 > [ 2.373189] df20: 00000088 c0d03d00 c165df74 c165df38 c0147bc4 > c0147378 c1313e74 c0b0c2c4 > [ 2.373925] df40: c10b1d2a c1206200 c165df74 c13d4980 c16b5580 > c0147900 c16b6f80 00000000 > [ 2.374628] df60: c1313e74 c165c000 c165dfac c165df78 c014feb4 > c014790c c13d49a4 c13d49a4 > [ 2.375345] df80: c165dfac c16b5580 c014fd3c 00000000 00000000 > 00000000 00000000 00000000 > [ 2.376080] dfa0: 00000000 c165dfb0 c0100150 c014fd48 00000000 > 00000000 00000000 00000000 > [ 2.376807] dfc0: 00000000 00000000 00000000 00000000 00000000 > 00000000 00000000 00000000 > [ 2.377534] dfe0: 00000000 00000000 00000000 00000000 00000013 > 00000000 00000000 00000000 > [ 2.378080] Backtrace: > [ 2.378297] [<c0556260>] (klist_put) from [<c0556340>] > (klist_iter_exit+0x24/0x30) > [ 2.378819] r7:c0d04d08 r6:c064373c r5:c165de6c r4:c165de3c > [ 2.379199] [<c055631c>] (klist_iter_exit) from [<c0641208>] > (bus_for_each_drv+0xa0/0xc8) > [ 2.379701] r5:c165de6c r4:00000000 > [ 2.379932] [<c0641168>] (bus_for_each_drv) from [<c0642f38>] > (__device_attach+0xf0/0x15c) > [ 2.380482] r7:c10846b8 r6:c13ae444 r5:c13ae400 r4:c0d04d08 > [ 2.380871] [<c0642e48>] (__device_attach) from [<c064390c>] > (device_initial_probe+0x1c/0x20) > [ 2.381453] r8:00000000 r7:c10846b8 r6:c13ae400 r5:c107d690 r4:c13ae400 > [ 2.381851] [<c06438f0>] (device_initial_probe) from [<c0642080>] > (bus_probe_device+0x94/0x9c) > [ 2.382364] [<c0641fec>] (bus_probe_device) from [<c064259c>] > (deferred_probe_work_func+0x8c/0xb8) > [ 2.382936] r7:c10846b8 r6:c10846a4 r5:c10846a4 r4:c13ae400 > [ 2.383266] [<c0642510>] (deferred_probe_work_func) from [<c01475a4>] > (process_one_work+0x238/0x594) > [ 2.383885] r9:00000000 r8:00000000 r7:c1225b00 r6:c1206200 > r5:c16b6f80 r4:c10846d4 > [ 2.384344] [<c014736c>] (process_one_work) from [<c0147bc4>] > (worker_thread+0x2c4/0x5f4) > [ 2.384893] r10:c0d03d00 r9:00000088 r8:ffffe000 r7:c1206218 > r6:c16b6f94 r5:c1206200 > [ 2.385341] r4:c16b6f80 > [ 2.385536] [<c0147900>] (worker_thread) from [<c014feb4>] > (kthread+0x178/0x194) > [ 2.386030] r10:c165c000 r9:c1313e74 r8:00000000 r7:c16b6f80 > r6:c0147900 r5:c16b5580 > [ 2.386540] r4:c13d4980 > [ 2.386742] [<c014fd3c>] (kthread) from [<c0100150>] > (ret_from_fork+0x14/0x24) > [ 2.387211] Exception stack(0xc165dfb0 to 0xc165dff8) > [ 2.387653] dfa0: 00000000 > 00000000 00000000 00000000 > [ 2.388374] dfc0: 00000000 00000000 00000000 00000000 00000000 > 00000000 00000000 00000000 > [ 2.389071] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 > [ 2.389546] r10:00000000 r9:00000000 r8:00000000 r7:00000000 > r6:00000000 r5:c014fd3c > [ 2.390037] r4:c16b5580 > [ 2.390376] Code: e1a07000 e1a06001 e3c44001 e1a00004 (e5945010) > [ 2.390836] ---[ end trace f293b13f591ee205 ]--- > [ 2.391580] ---[ end Kernel panic - not syncing: Fatal exception ]--- > > > >>> -Saravana > >>> > >>> [1] - https://lore.kernel.org/lkml/CAGETcx8b228nDUho3cX9AAQ-pXOfZTMv8cj2vhdx9yc_pk8q+A@xxxxxxxxxxxxxx/ > >>> . > >>> > > . > >
