The following kernel warning noticed on linux-next on arm64 juno-r2 device.
Linux version 5.6.0-rc5-next-20200316 (TuxBuild@ccdbe23f0d06) (gcc version 9.2.1 20191130 (Debian 9.2.1-21)) #1 SMP PREEMPT Mon Mar 16 07:40:45 UTC 2020
[ 0.002822] ------------[ cut here ]------------ [ 0.002840] WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:4156 __clk_put+0xfc/0x130 [ 0.002846] Modules linked in: [ 0.002859] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.6.0-rc5-next-20200316 #1 [ 0.002865] Hardware name: ARM Juno development board (r2) (DT) [ 0.002873] pstate: 20000005 (nzCv daif -PAN -UAO) [ 0.002882] pc : __clk_put+0xfc/0x130 [ 0.002891] lr : clk_put+0xc/0x18 [ 0.002896] sp : ffff80001003bba0 [ 0.002902] x29: ffff80001003bba0 x28: 0000000000000000 [ 0.002911] x27: 0000000000000000 x26: ffff800011c56000 [ 0.002919] x25: ffff800011c56490 x24: 0000000000000001 [ 0.002928] x23: ffff00097effdae8 x22: 0000000000000001 [ 0.002936] x21: ffff000975cc8000 x20: fffffffffffffdfb [ 0.002945] x19: fffffffffffffdfb x18: 0000000000000001 [ 0.002953] x17: 00000000e80423fd x16: 00000000e66966f2 [ 0.002961] x15: ffffffffffffffff x14: ffffffffff000000 [ 0.002970] x13: ffffffffffffffff x12: 0000000000000018 [ 0.002978] x11: 0000000000000028 x10: 0101010101010101 [ 0.002987] x9 : ffffffffffffffff x8 : 7f7f7f7f7f7f7f7f [ 0.002995] x7 : 6b61ff726b6b6462 x6 : 000000000080636c [ 0.003003] x5 : ffff00097eff3d30 x4 : 0000000000000000 [ 0.003011] x3 : 0000000000000001 x2 : 0000000000000001 [ 0.003019] x1 : 1989cb6049749c00 x0 : fffffffffffffdfb [ 0.003028] Call trace: [ 0.003037] __clk_put+0xfc/0x130 [ 0.003045] clk_put+0xc/0x18 [ 0.003057] topology_parse_cpu_capacity+0x100/0x180 [ 0.003065] get_cpu_for_node+0x3c/0x80 [ 0.003074] parse_cluster+0x1c8/0x2dc [ 0.003082] parse_cluster+0x84/0x2dc [ 0.003091] init_cpu_topology+0x80/0x114 [ 0.003101] smp_prepare_cpus+0x24/0x100 [ 0.003110] kernel_init_freeable+0xbc/0x23c [ 0.003120] kernel_init+0x10/0x100 [ 0.003129] ret_from_fork+0x10/0x18 [ 0.003138] ---[ end trace 33c8be449b41381b ]---
[ 33.765558] ------------[ cut here ]------------ [ 33.770234] arm-smmu 2b600000.iommu: deferred probe timeout, ignoring dependency [ 33.770269] WARNING: CPU: 1 PID: 331 at drivers/base/dd.c:270 driver_deferred_probe_check_state+0x40/0x60 [ 33.787249] Modules linked in: fuse [ 33.790744] CPU: 1 PID: 331 Comm: kworker/1:2 Tainted: G W 5.6.0-rc5-next-20200316 #1 [ 33.799892] Hardware name: ARM Juno development board (r2) (DT) [ 33.805824] Workqueue: events deferred_probe_work_func [ 33.810969] pstate: 60000005 (nZCv daif -PAN -UAO) [ 33.815765] pc : driver_deferred_probe_check_state+0x40/0x60 [ 33.821429] lr : driver_deferred_probe_check_state+0x40/0x60 [ 33.827092] sp : ffff80001254bac0 [ 33.830404] x29: ffff80001254bac0 x28: ffff8000119f7000 [ 33.835724] x27: 0000000000000000 x26: ffff800011db3ce8 [ 33.841043] x25: 0000000000000001 x24: ffff800011b92228 [ 33.846359] x23: ffff0009754a1410 x22: fffffffffffffffe [ 33.851676] x21: ffff0009756d0e00 x20: ffff0009754a1410 [ 33.856992] x19: ffff0009754a1410 x18: 0000000000000010 [ 33.862308] x17: 0000000000000000 x16: 0000000000000000 [ 33.867624] x15: ffff0009756d1270 x14: 646e657065642067 [ 33.872940] x13: 6e69726f6e676920 x12: 2c74756f656d6974 [ 33.878259] x11: 2065626f72702064 x10: 6572726566656420 [ 33.883576] x9 : 3a756d6d6f692e30 x8 : 3030303036623220 [ 33.888892] x7 : 756d6d732d6d7261 x6 : ffff800011c058dc [ 33.894207] x5 : 0000000000000000 x4 : 0000000000000000 [ 33.899523] x3 : 00000000ffffffff x2 : ffff80096d96d000 [ 33.904839] x1 : ff65453dc5583b00 x0 : 0000000000000000 [ 33.910155] Call trace: [ 33.912605] driver_deferred_probe_check_state+0x40/0x60 [ 33.917922] __genpd_dev_pm_attach+0x1a0/0x1b0 [ 33.922367] genpd_dev_pm_attach+0x58/0x68 [ 33.926466] dev_pm_domain_attach+0x48/0x50 [ 33.930656] platform_drv_probe+0x38/0xa0 [ 33.934668] really_probe+0xd4/0x318 [ 33.938243] driver_probe_device+0x54/0xe8 [ 33.942340] __device_attach_driver+0x80/0xb8 [ 33.946699] bus_for_each_drv+0x74/0xc0 [ 33.950535] __device_attach+0xdc/0x138 [ 33.954371] device_initial_probe+0x10/0x18 [ 33.958556] bus_probe_device+0x90/0x98 [ 33.962392] deferred_probe_work_func+0x6c/0xa0 [ 33.966926] process_one_work+0x19c/0x320 [ 33.970936] worker_thread+0x1f0/0x420 [ 33.974685] kthread+0xf0/0x120 [ 33.977827] ret_from_fork+0x10/0x18 [ 33.981402] ---[ end trace 33c8be449b41381d ]---
ref: https://lkft.validation.linaro.org/scheduler/job/1291796#L642
Quoting Naresh Kamboju (2020-03-16 02:05:24)
The following kernel warning noticed on linux-next on arm64 juno-r2 device.
Linux version 5.6.0-rc5-next-20200316 (TuxBuild@ccdbe23f0d06) (gcc version 9.2.1 20191130 (Debian 9.2.1-21)) #1 SMP PREEMPT Mon Mar 16 07:40:45 UTC 2020
[ 0.002822] ------------[ cut here ]------------ [ 0.002840] WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:4156 __clk_put+0xfc/0x130 [ 0.002846] Modules linked in: [ 0.002859] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.6.0-rc5-next-20200316 #1 [ 0.002865] Hardware name: ARM Juno development board (r2) (DT) [ 0.002873] pstate: 20000005 (nzCv daif -PAN -UAO) [ 0.002882] pc : __clk_put+0xfc/0x130 [ 0.002891] lr : clk_put+0xc/0x18
Looks like the code is wrong. It calls of_clk_get() and then unconditionally calls clk_put() on whatever is returned, including an error pointer which we warn about.
WARN_ON_ONCE(IS_ERR(clk))
in __clk_put().
[ 0.002896] sp : ffff80001003bba0 [ 0.002902] x29: ffff80001003bba0 x28: 0000000000000000 [ 0.002911] x27: 0000000000000000 x26: ffff800011c56000 [ 0.002919] x25: ffff800011c56490 x24: 0000000000000001 [ 0.002928] x23: ffff00097effdae8 x22: 0000000000000001 [ 0.002936] x21: ffff000975cc8000 x20: fffffffffffffdfb [ 0.002945] x19: fffffffffffffdfb x18: 0000000000000001 [ 0.002953] x17: 00000000e80423fd x16: 00000000e66966f2 [ 0.002961] x15: ffffffffffffffff x14: ffffffffff000000 [ 0.002970] x13: ffffffffffffffff x12: 0000000000000018 [ 0.002978] x11: 0000000000000028 x10: 0101010101010101 [ 0.002987] x9 : ffffffffffffffff x8 : 7f7f7f7f7f7f7f7f [ 0.002995] x7 : 6b61ff726b6b6462 x6 : 000000000080636c [ 0.003003] x5 : ffff00097eff3d30 x4 : 0000000000000000 [ 0.003011] x3 : 0000000000000001 x2 : 0000000000000001 [ 0.003019] x1 : 1989cb6049749c00 x0 : fffffffffffffdfb [ 0.003028] Call trace: [ 0.003037] __clk_put+0xfc/0x130 [ 0.003045] clk_put+0xc/0x18 [ 0.003057] topology_parse_cpu_capacity+0x100/0x180
Looks like Greg picked up this patch[1] as commit b8fe128dad8f ("arch_topology: Adjust initial CPU capacities with current freq") from the list. Not sure it's correct though and I haven't looked in any more detail. At least, not calling clk_put() unless it is a valid pointer will work to quiet this warning.
[1] https://lore.kernel.org/r/20200113034815.25924-1-jeffy.chen@rock-chips.com
Hi Stephen,
On 03/17/2020 02:12 AM, Stephen Boyd wrote:
Looks like Greg picked up this patch[1] as commit b8fe128dad8f ("arch_topology: Adjust initial CPU capacities with current freq") from the list. Not sure it's correct though and I haven't looked in any more detail. At least, not calling clk_put() unless it is a valid pointer will work to quiet this warning.
[1] https://lore.kernel.org/r/20200113034815.25924-1-jeffy.chen@rock-chips.com
Sorry, i made a stupid mistake... Sending the fix now, thanks for checking that.
-
JeffyChen -
Naresh Kamboju -
Stephen Boyd