On Wed, 14 Jan 2009, Ritesh Raj Sarraf wrote: > Okay!! I think I now have the correct steps to reproduce it consistently. ... > The above result is from a freshly booted linux with the same suspected faulty > USB HDD enclosure. I ran it on 2 kernels, one standard and one debug, and both > gave similar results. > So shouldn't be faulty hardware. > > > So then with my standard kernel, I booted + hibernated and then resumed and > then again ran the I/O. Here are the same results. ... > So this seems to be happening on my laptop when the OS has used the > hibernation feature. I'm of-course doing a luksClose and USB device > disconnection before hibernation. And presumably you reconnect the USB device after resuming. That reconnect appears to be where the problem arises. > Here's the usb device listing after hibernation/resume. > > rrs@learner:~$ cat /tmp/lsusb.suspend > Bus 005 Device 005: ID 046d:08c6 Logitech, Inc. QuickCam for DELL Notebooks > Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub > Bus 004 Device 007: ID 05e3:0702 Genesys Logic, Inc. USB 2.0 IDE Adapter > Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub > Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub > Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub > Bus 001 Device 005: ID 046d:c00c Logitech, Inc. Optical Wheel Mouse > Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Notice that the IDE Adapter is now attached to a 1.1 bus rather than a 2.0 bus. That's why it's running so much slower. > And here's the usb device listing after a fresh boot. > > rrs@learner:~$ lsusb > Bus 005 Device 004: ID 05e3:0702 Genesys Logic, Inc. USB 2.0 IDE Adapter > Bus 005 Device 003: ID 046d:08c6 Logitech, Inc. QuickCam for DELL Notebooks > Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub > Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 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 001 Device 004: ID 046d:c00c Logitech, Inc. Optical Wheel Mouse > Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Try building a kernel with CONFIG_USB_DEBUG enabled, and post the dmesg log showing what happens during the disconnect, hibernate, resume, and reconnect. You could also try the same thing with no disconnect/reconnect. Just leave the IDE adapter plugged in the whole time. Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
