Most recent kernel where this bug did not occur: 2.6.14 Distribution: Gentoo Hardware Environment: Asus M6V notebook Problem Description: If I do suspend to RAM and then suspend to disk (swsusp or suspend2), after resume every proces which tries to read from /proc/acpi/* freezes, starts to take 100% of CPU and can't be killed (even with kill -9). The whole system does not crash, and there's no output in dmesg. Repeated suspend to ram or suspend to disk is OK, only this combination triggers it. Steps to reproduce: echo mem > /sys/power/state echo disk > /sys/power/state cat /proc/acpi/thermal_zone/THRM/temperature lspci output: 0000:00:00.0 Host bridge: Intel Corporation Mobile 915GM/PM/GMS/910GML Express Processor to DRAM Controller (rev 03) 0000:00:01.0 PCI bridge: Intel Corporation Mobile 915GM/PM Express PCI Express Root Port (rev 03) 0000:00:1b.0 Class 0403: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller (rev 04) 0000:00:1d.0 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #1 (rev 04) 0000:00:1d.1 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #2 (rev 04) 0000:00:1d.2 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #3 (rev 04) 0000:00:1d.3 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #4 (rev 04) 0000:00:1d.7 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB2 EHCI Controller (rev 04) 0000:00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev d4) 0000:00:1f.0 ISA bridge: Intel Corporation 82801FBM (ICH6M) LPC Interface Bridge (rev 04) 0000:00:1f.1 IDE interface: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) IDE Controller (rev 04) 0000:01:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8001 Gigabit Ethernet Controller (rev 13) 0000:01:01.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev b3) 0000:01:01.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C552 IEEE 1394 Controller (rev 08) 0000:01:01.2 Class 0805: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 17) 0000:01:01.3 System peripheral: Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter (rev 08) 0000:01:01.4 System peripheral: Ricoh Co Ltd xD-Picture Card Controller (rev 03) 0000:01:02.0 Network controller: Intel Corporation PRO/Wireless 2915ABG MiniPCI Adapter (rev 05) 0000:03:00.0 VGA compatible controller: ATI Technologies Inc M24 1P [Radeon Mobility X600] Additional information: I was pointed here from LKML, the original post is here: http://lkml.org/lkml/2006/4/19/135 The problem happens after SMBus was enabled in drivers/pci/quirks.c (commit 89fbb69c4f285019ba5e029963dc11cc6beb078a, the patch originates here: http://lists.lm-sensors.org/pipermail/lm-sensors/2005-September/013663.html ). But it doesn't matter whether I2C and Hardware Monitoring modules are loaded, only whether SMBus is enabled.
Created attachment 7905 [details] My kernel configuration
Created attachment 7906 [details] Output of Alt+SysRq+T
So in your dmesg you have: "PCI: Trying to enable ICH6 SMBus. RCBA base 0x%x relocated 0x%x \n" and if you disable the new quirk, which asus_hides_smbus=1 then this issue goes away? after the resume, does even the following hang? # cat /proc/acpi/info
> So in your dmesg you have: > "PCI: Trying to enable ICH6 SMBus. RCBA base 0x%x relocated 0x%x \n" The message is "PCI: Enabled ICH6/i801 SMBus device" >and if you disable the new quirk, which asus_hides_smbus=1 >then this issue goes away? Yes. > after the resume, does even the following hang? > # cat /proc/acpi/info I tried it under 2.6.17-rc2 without X11 and any daemons running. It acts differently, and I hope it's more helpful: After resume, i can read everything in /proc/acpi except /proc/acpi/thermal_zone/THRM/temperature. Reading from this file still hangs. But then I can still read most files in /proc/acpi, with only some exceptions, eg. /proc/acpi/asus/info, /proc/acpi/video/VGA/TVOD. And only the first process which tried to read from /proc/acpi/thermal_zone/THRM/temperature takes 100% CPU, others just freeze. Maybe there's some conflict between reading temperature via acpi and via SMBus?
It seems the problem is fixed in 2.6.17-rc6.
Fixed in 2.6.17-rc6.