Comment 360 for bug 124406

Daniel J Blueman (watchmaker) wrote :

I've been observing this happen once a week across a wide range of x86 systems with USB keyboards in the last (5?) years.

Since I've observed it in the virtual terminal and have never observed this with PS/2 keyboards, I suspect there is an event race condition in the USB input stack, eg a missing write barrier.

When I increase system latency, it looks like there's more chance of it happening, so this feels like MMIO write ordering causing a lost key up event.