System Interrupts high CPU when any usb device gets plugged in

[hazzoz]

Whenever a USB device is plugged into my laptop (any of the USB ports), the CPU usage goes way up. It stays up even when the device is then unplugged, and the only way to bring it back down is to either reboot, or to go into "sleep" (when Windows resumes the problem is gone).

The Windows 7 resource monitor indicates that the problem is System Interrupts - Deferred Procedure Calls and Interrupt Service Routines. .

I have updated my drivers for each thing, and that has not helped. Not has lots of Google searches on this problem.

Running Windows 7 Home Professional 64 bit, on a Toshiba Portege R705-P41.

Any ideas? Thanks in advance.

 

[whs]

A lot of DPCs usually point to a driver problem. Run this program (when the problem occurs) and see whether it gives you any clues. http://www.thesycon.de/eng/latency_check.shtml

 

[hazzoz]

Thanks. I've now done that. However the latency readings are no different whether the problem is occurring or not. I.e. it is mostly in the green (sub-500us), with a single spike to 3000-4000us every 30 seconds.
Any other thoughts?

 

[whs]

Any idea what process could become active every 30 seconds.

 

[hazzoz]

I watched the DPC latency checker as I disabled items in device manager. The FIRST thing I disabled led to no more spikes. It was:
Intel(R) 82577LC Gigabit Network Connection, under Network adapters.
I only use wireless as apposed to an ethernet cable, so will just leave it disabled.

 

[hazzoz]

This driver seems to be the source of my other (bigger) problem too. I will update the driver, and if that doesn't work, will leave it disabled.
Many thanks whs!!

 

[whs]

I am glad you are making progress. Is there anything else I can do for you ??

 

[hazzoz]

No, but I'll come back if I have further issues.
Cheers.