On Fri, 2015-31-07 at 12:08:58 UTC, Paul Bolle wrote:
> wf_unregister_client() increments the client count when a client
> unregisters. That is obviously incorrect. Decrement that client count
> instead.
>
> Fixes: 75722d3992f5 ("[PATCH] ppc64: Thermal control for SMU based machines")
>
> Signed-off-by: Paul Bolle <pebo...@tiscali.nl>
> ---
> cross-compiled only. I don't have a PPC machine at hand, sorry. And this
> does need some run-time testing, I'd day.
>
> windfarm_corex_exit() contains:
> BUG_ON(wf_client_count != 0);
>
> I wonder why that, apparently. never triggered.
Hmm interesting.
A quick test here on an iMacG5 shows that we get into a state where we can't
remove windfarm_core:
$ lsmod
Module Size Used by
windfarm_smu_sensors 7549 2
windfarm_core 15391 1 windfarm_smu_sensors
Which means we can't trigger windfarm_core_exit() and the BUG_ON().
I also get an oops when removing windfarm_lm75_sensor, so I suspect there are
gremlins in the module ref counting for windfarm.
I'll merge this as probably correct.
------------[ cut here ]------------
WARNING: at ../kernel/module.c:1116
Modules linked in: windfarm_lm75_sensor(-) windfarm_smu_sensors
windfarm_smu_controls windfarm_core [last unloaded: windfarm_cpufreq_clamp]
CPU: 0 PID: 2860 Comm: modprobe Not tainted
4.2.0-rc2-00043-gf4e908dd3cbe-dirty #2
task: c00000003d9c4fe0 ti: c00000003df20000 task.ti: c00000003df20000
NIP: c0000000000d62d0 LR: d0000000004338bc CTR: c0000000000d62a0
REGS: c00000003df23660 TRAP: 0700 Not tainted
(4.2.0-rc2-00043-gf4e908dd3cbe-dirty)
MSR: 9000000000029032 <SF,HV,EE,ME,IR,DR,RI> CR: 82002884 XER: 20000000
SOFTE: 1
GPR00: d0000000004338b0 c00000003df238e0 c000000000b27800 d000000000474b00
GPR04: c00000003d185900 0000000000000001 000000003e5de000 000000000000175c
GPR08: c000000000a2c068 0000000000000001 ffffffffffffffff d0000000004343c0
GPR12: c0000000000d62a0 c00000000ffff000 0000000000000004 0000000000000001
GPR16: 0000000000000000 0000000000000000 0000000000000000 00000000ffe108bc
GPR20: 0000000000000000 00000000209b0278 0000000000000000 0000000000000001
GPR24: 00000000ffe11915 00000000209b0008 00000000209b02ac 0000000000000000
GPR28: 0000000000000000 c00000003d1b3c80 0000000000000000 d000000000474b00
NIP [c0000000000d62d0] .module_put+0x30/0x40
LR [d0000000004338bc] .wf_put_sensor+0x9c/0xf0 [windfarm_core]
Call Trace:
[c00000003df238e0] [d0000000004338b0] .wf_put_sensor+0x90/0xf0
[windfarm_core] (unreliable)
[c00000003df23960] [d000000000474020] .wf_lm75_remove+0x20/0x40
[windfarm_lm75_sensor]
[c00000003df239d0] [c00000000058cb8c] .i2c_device_remove+0x7c/0xb0
[c00000003df23a50] [c000000000450dd4] .__device_release_driver+0xb4/0x180
[c00000003df23ad0] [c000000000451a08] .driver_detach+0x138/0x180
[c00000003df23b70] [c000000000450720] .bus_remove_driver+0x70/0xf0
[c00000003df23bf0] [c0000000004523a8] .driver_unregister+0x38/0x70
[c00000003df23c70] [c00000000058d718] .i2c_del_driver+0x28/0x40
[c00000003df23cf0] [d0000000004743fc] .wf_lm75_driver_exit+0x18/0x2cc
[windfarm_lm75_sensor]
[c00000003df23d60] [c0000000000d82bc] .SyS_delete_module+0x18c/0x250
[c00000003df23e30] [c000000000007c98] system_call+0x38/0xd0
Instruction dump:
2c230000 4d820020 392302e0 7c2004ac 7d404828 2c0a0001 394affff 41c00010
7d40492d 40c2ffec 7c0004ac 55490ffe <0b090000> 4e800020 60000000 60000000
---[ end trace 013348a741cf9320 ]---
cheers
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