Got it. Thanks.
My laptop does not have USB 3.0. It says on the HP Product Specifications page that it has 3 USB 2.0 ports. I have tried the USBBusFix option in the boot loader, but that just made all of the ports unresponsive.
Code:
May 2 09:22:37 localhost kernel[0]: USBF: 0.252 AppleUSBEHCI::CheckSleepCapability - controller will be unloaded across sleep
May 2 09:22:37 localhost kernel[0]: USBF: 0.254 AppleUSBEHCI::CheckSleepCapability - controller will be unloaded across sleep
May 2 09:22:37 localhost kernel[0]: USBF: 0.259 AppleUSBEHCI::CheckSleepCapability - controller will be unloaded across sleep
May 2 09:22:41 localhost com.apple.usbmuxd[23]: usbmuxd-327.4 on Feb 12 2014 at 14:54:33, running 64 bit
May 2 09:25:54 localhost kernel[0]: mcache: 4 CPU(s), 64 bytes CPU cache line sizeUSBF: 0.351 AppleUSBEHCI::CheckSleepCapability - controller will be unloaded across sleep
May 2 09:25:54 localhost kernel[0]: USBF: 0.352 AppleUSBEHCI::CheckSleepCapability - controller will be unloaded across sleep
May 2 09:25:54 localhost kernel[0]: USBF: 0.353 AppleUSBEHCI::CheckSleepCapability - controller will be unloaded across sleep
May 2 09:25:54 localhost kernel[0]: USBF: 0.358 AppleUSBEHCI::CheckSleepCapability - controller will be unloaded across sleep
May 2 09:26:08 localhost com.apple.usbmuxd[26]: usbmuxd-327.4 on Feb 12 2014 at 14:54:33, running 64 bit
May 2 09:26:17 localhost kernel[0]: AppleUSBEthernetHost::powerStateChangeOccurred: intf is not enabled, ignoring ... st: 0
May 2 10:13:24 localhost kernel[0]: USBF: 0.241 AppleUSBEHCI:: unable to get filterInterruptEventSource
May 2 10:13:24 localhost kernel[0]: USBF: 0.242 AppleUSBEHCI::UIMInitialize - Error occurred (0xe00002be)
May 2 10:13:24 localhost kernel[0]: USBF: 0.247 AppleUSBEHCI::CheckSleepCapability - controller will be unloaded across sleep
May 2 10:13:24 localhost kernel[0]: USBF: 0.248 AppleUSBEHCI::CheckSleepCapability - controller will be unloaded across sleep
I think these are some USB-related errors...
I previously fixed the problem by deleting AppleHPET.kext, but I know that I can't do that now as I need it for AppleIntelCPUPowerManagement.