On May 6 I posted a blog entitled “Windows Hardware Problem Fixed: Mystery Started” that recounts my problems with the fingerprint scanner on my HP dv6t-2300 notebook PC. In that posting, I reported that my problems were fixed by the latest round of additions to Windows Update. And indeed, that’s exactly how things looked until I took my notebook on the road for a business trip this week.
The issue with the device going off-line when the unit goes to sleep is definitely resolved. But that issue remains present when the unit hibernates. Upon its wake-up (and all subsequent wake-ups) from hibernation, the fingerprint scanner fails to be detected when Windows does device enumeration during boot-up. The only way for me to regain access to the device after that is to restart it, or to shut it down all the way, after which the device does get detected the next time I boot up the machine.
So clearly, the issue is with what happens to the driver when the device hibernates. I can live with this situation, because when I’m on wall socket power in the office using that machine, it’s set not to hibernate. Hibernation only kicks in when the unit is running off battery, as a default setting in the HP Recommended power management scheme for that machine.
It just goes to show you that not all apparent fixes are what they seem. I’d hoped all my issues with the driver for that VFS301 fingerprint sensor from Validity Sensors were over and done with, but apparently HP, Validity Sensors, or whoever’s responsible for making sure devices show up after hibernation during device enumeration, still have some work to do. But that’s life in the Windows trenches. If and when I find a fix, I’ll report back.