Hi, (I'm posting from outside, so please CC me on a reply.) Some time ago I updated my kernel to 2.6.23.14 (vanilla) from something pre-20. My system has a w83627ehf chip (the chip is labeled like that) and the support for this chip seemed to have improved. However my cpu fan "occasionally" stops spinning. This happened three times at the time of this writing. It seems to happen when the system is completely idle. As a result the cpu heats up and maybe destroying or damaging itself over time. This is BAD! I therefore tried to play with the /sys/devices/platform/w83627ehf.*/ interface. Changing the files pwm2* "sometimes" has an barely predictable effect on the cpu fan. I was for instance able to start the fan again by writing 2 to pwm2_enable the last time it stopped. However I cannot disable the fan now by writing 0 to pwm2 which sometimes worked before. Most of my writing data to these files seems to get ignored. The only thing I really need now is a stable cpu fan. Can I somehow lock it to maximum speed or something similar? Can I somehow run w83627ehf with reduced functionality (like no longer modifying the fan at all)? Please help me debug this. Do you want any other information not found below? Helmut Grohne root@# i2cdetect ... Installed I2C busses: i2c-0 smbus SMBus Via Pro adapter at 5000 root@# i2cdetect 0 WARNING! This program can confuse your I2C bus, cause data loss and worse! I will probe file /dev/i2c-0. I will probe address range 0x03-0x77. Continue? [Y/n] y 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: 50 51 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- 69 -- -- -- -- -- -- 70: -- -- -- -- -- -- -- -- root@# isadump 0x295 0x296 WARNING! Running this program can cause system crashes, data loss and worse! I will probe address register 0x295 and data register 0x296. Continue? [Y/n] y 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: 01 01 01 ff 03 00 01 30 01 b1 01 01 3c 3c 01 01 10: 01 ff 10 01 00 01 01 3c 43 07 00 00 57 00 00 c7 20: 98 e4 cf cf ff c7 c7 26 ff 04 ff 01 00 01 df fd 30: ef 5f b6 01 dc 01 01 01 ed 01 28 01 05 01 1f ff 40: 01 ff a8 de ff ff 00 f0 2d ff 40 c1 10 15 01 a3 50: 2c 00 00 01 00 50 00 ff ff ff ff ff ff ff ff ff 60: 01 ff 40 01 01 01 3c ff 01 ff 01 ff ff ff ff ff 70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff root@# cat sensor_fix.sh #!/bin/bash # this script is now invoked every 5 minutes from cron to try and fix # the fan automatically. cd /sys/devices/platform/w83627ehf.* || exit 1 test $(<fan2_input) -le 2000 || exit 0 echo fan not spinning while :; do echo "trying pwm2_enable 2" echo 2 > pwm2_enable sleep 1 test $(<fan2_input) -le 2000 || exit 0 echo "trying pwm2 255" echo 255 > pwm2 sleep 1 test $(<fan2_input) -le 2000 || exit 0 echo "trying pwm2_enable 1" echo 1 > pwm2_enable sleep 1 test $(<fan2_input) -le 2000 || exit 0 echo "trying pwm2 255" echo 255 > pwm2 sleep 1 test $(<fan2_input) -le 2000 || exit 0 echo "trying pwm2_target 1000" echo 1000 > pwm2_target sleep 1 test $(<fan2_input) -le 2000 || exit 0 done root@# exit helmut@$ dmesg ... w83627ehf: Found W83627EHG chip at 0x290 ... helmut@$ dpkg -k lm-sensors ... ii lm-sensors 1:3.0.1-2 utilities to read temperature/voltage/fan sensors helmut@$ lspci 00:00.0 Host bridge: VIA Technologies, Inc. K8T890 Host Bridge 00:00.1 Host bridge: VIA Technologies, Inc. K8T890 Host Bridge 00:00.2 Host bridge: VIA Technologies, Inc. K8T890 Host Bridge 00:00.3 Host bridge: VIA Technologies, Inc. K8T890 Host Bridge 00:00.4 Host bridge: VIA Technologies, Inc. K8T890 Host Bridge 00:00.5 PIC: VIA Technologies, Inc. K8T890 I/O APIC Interrupt Controller 00:00.7 Host bridge: VIA Technologies, Inc. K8T890 Host Bridge 00:01.0 PCI bridge: VIA Technologies, Inc. VT8237 PCI bridge [K8T800/K8T890 South] 00:02.0 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller 00:03.0 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller 00:03.1 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller 00:03.2 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller 00:03.3 PCI bridge: VIA Technologies, Inc. K8T890 PCI to PCI Bridge Controller 00:0c.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10) 00:0f.0 IDE interface: VIA Technologies, Inc. VIA VT6420 SATA RAID Controller (rev 80) 00:0f.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06) 00:10.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81) 00:10.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81) 00:10.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81) 00:10.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81) 00:10.4 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 86) 00:11.0 ISA bridge: VIA Technologies, Inc. VT8237 ISA bridge [KT600/K8T800/K8T890 South] 00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller (rev 60) 00:11.6 Communication controller: VIA Technologies, Inc. AC'97 Modem Controller (rev 80) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 02:00.0 VGA compatible controller: nVidia Corporation NV44 [GeForce 6200 TurboCache(TM)] (rev a1) 05:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8053 PCI-E Gigabit Ethernet Controller (rev 19) helmut@$ lsmod ... w83627ehf 26184 0 ac 6728 0 cpufreq_userspace 5228 0 cpufreq_ondemand 10064 1 cpufreq_powersave 2368 0 powernow_k8 15584 1 freq_table 5520 3 cpufreq_stats,cpufreq_ondemand,powernow_k8 hwmon_vid 4160 1 w83627ehf i2c_viapro 10584 0 k8temp 6848 0 hwmon 4104 2 w83627ehf,k8temp i2c_core 28800 1 i2c_viapro thermal 18336 0 processor 38952 2 powernow_k8,thermal fan 6216 0 ... helmut@$