Arch Linux

What kernel version are you using?

According to ChangeLog:
USB suspend interface has changed with kernels 2.6.35 and above. (Debian BTS: #589000)

There are other USB related changes that might explain the problem. You might want to ask upstream about it. As the package doesn't involve any compilation, it's probably an upstream issue.

Am using standard kernel 2.6.37-5 from Core.
This is odd, because I can keep this kernel and laptop-mode-tools-1.55-2 work fine, but not 1.56-1.

I had the same problem, it was not possible to connect usb, usb ports were
suspended.
I had to add the USB ID to the list AUTOSUSPEND_USBID_BLACKLIST.
What I notice is that it not recognizes the value of the configuration variable
CONTROL_USB_AUTOSUSPEND in usb-autosuspend.conf file in / etc/laptop-
mode / conf.d

@xyzwqt: Thanks for the confirmation. Version 1.56 certainly sets ENABLE_LAPTOP_MODE_TOOLS=1 in /etc/laptop-mode/laptop-mode.conf, automatically enabling everything, including /etc/laptop-mode/conf.d/usb-autosuspend.conf. And I agree with you, it seems the variable to switch this off (CONTROL_USB_AUTOSUSPEND=0) is ineffective.

However, I've found that USB devices do work on my Asus Eee 701 netbooks with laptop-mode-tools 1.56. It's only my Dell Inspiron 1525 which is failing with this version.

Did anyone reported this upstream?

No, but just confirmed that the same thing happens after all the recent Arch updates are applied.
I note that the file /etc/laptop-mode/conf.d/usb-autosuspend.conf contains a comment:

"NOTE: Some USB devices claim they support autosuspend, but implement it in a broken way. This can mean keyboards losing keypresses, or optical mice turning their LED completely off. If you have a device that misbehaves, add its USB ID to the blacklist below and complain to your hardware vendor."

The comment refers more to a specific device than a blanket suspension of USB devices, but I wonder if this is indeed a Dell-specific problem? xyzwqt didn't report what type of laptop he was using, unfortunately.

I have a Acer 5542. I never had problems with my USB devices. Only with the last update.
I had problems with any flash drive and a Samsung external drive.
But the devices were plugged in at boot does not suffer problems. Only if I disconnect and reconnect them they stop working.

[#####linux ~]$ lspci
00:00.0 Host bridge: Advanced Micro Devices [AMD] RS880 Host Bridge
00:01.0 PCI bridge: Acer Incorporated [ALI] Device 9602
00:04.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (PCIE port 0)
00:06.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (PCIE port 2)
00:11.0 SATA controller: ATI Technologies Inc SB700/SB800 SATA Controller [AHCI mode]
00:12.0 USB Controller: ATI Technologies Inc SB700/SB800 USB OHCI0 Controller
00:12.1 USB Controller: ATI Technologies Inc SB700 USB OHCI1 Controller
00:12.2 USB Controller: ATI Technologies Inc SB700/SB800 USB EHCI Controller
00:13.0 USB Controller: ATI Technologies Inc SB700/SB800 USB OHCI0 Controller
00:13.1 USB Controller: ATI Technologies Inc SB700 USB OHCI1 Controller
00:13.2 USB Controller: ATI Technologies Inc SB700/SB800 USB EHCI Controller
00:14.0 SMBus: ATI Technologies Inc SBx00 SMBus Controller (rev 3c)
00:14.2 Audio device: ATI Technologies Inc SBx00 Azalia (Intel HDA)
00:14.3 ISA bridge: ATI Technologies Inc SB700/SB800 LPC host controller
00:14.4 PCI bridge: ATI Technologies Inc SBx00 PCI to PCI Bridge
00:18.0 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor HyperTransport Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Miscellaneous Control
00:18.4 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Link Control
01:05.0 VGA compatible controller: ATI Technologies Inc M880G [Mobility Radeon HD 4200]
01:05.1 Audio device: ATI Technologies Inc RS880 Audio Device [Radeon HD 4200]
03:00.0 Ethernet controller: Broadcom Corporation NetLink BCM5784M Gigabit Ethernet PCIe (rev 10)
09:00.0 Network controller: Atheros Communications Inc. AR928X Wireless Network Adapter (PCI-Express) (rev 01)

[#####linux ~]$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 003: ID 064e:a103 Suyin Corp. Acer/HP Integrated Webcam [CN0314]
Bus 003 Device 002: ID 0458:003a KYE Systems Corp. (Mouse Systems) NetScroll+ Mini Traveler / Genius NetScroll 120
Bus 005 Device 002: ID 0458:0708 KYE Systems Corp. (Mouse Systems)

Sorry for my English from google Traslator.

I can confirm this too, also with a Dell, an M101z (Inspiron 1120).

Is this still a problem with lmt-1.57? Has it been reported to the application developers?

FWIW this may be an issue with having both lmt and pm-utils installed on the same system. Debian and Ubuntu recently added conflicts between the two packages cause they both provide laptop-mode. pm-utils: /usr/lib/pm-utils/power.d/laptop-mode

You may want to check if your troubles disappear if you remove one of the two.

Seems fixed for me now with 1.57. I do have both pm-utils and lmt installed.

Alas, no change for me with v1.57.