Hi, There is a bug in the processing of the Fn key on the first generation of Dell XPS 13 laptops (at least models L321X and L322X have the problem). It happens with the combinations for Home, End, Page Up and Page Down keys, achieved with pressing Fn with respectively Left, Right, Up and Down. If the Fn key is released before the other key, the release of the other key is not passed through. In that case, an auto-repeat of the key may activate itself until any other key is pressed. This is confirmed by running evtest: Event: time 1485332907.361701, type 4 (EV_MSC), code 4 (MSC_SCAN), value cf Event: time 1485332907.361701, type 1 (EV_KEY), code 107 (KEY_END), value 1 Event: time 1485332907.659714, type 4 (EV_MSC), code 4 (MSC_SCAN), value cd The second MSC_SCAN happens when the Fn key is released and after it, until any key is pressed again, the End key is considered pressed and auto-repeating eventually starts. Another similar situation happens if for instance the Right key is pressed, then the Fn key is pressed before the Right key is released. The subsequent release of the Right key is not passed through: Event: time 1485333101.589438, type 4 (EV_MSC), code 4 (MSC_SCAN), value cd Event: time 1485333101.589438, type 1 (EV_KEY), code 106 (KEY_RIGHT), value 1 Event: time 1485333101.959561, type 4 (EV_MSC), code 4 (MSC_SCAN), value cf Interestingly, after such an event, if the not-released-key is pressed again, the key press is not registered by whatever application has the focus and evtest shows the following: Event: time 1485333306.755393, type 4 (EV_MSC), code 4 (MSC_SCAN), value cd Event: time 1485333306.755393, type 1 (EV_KEY), code 106 (KEY_RIGHT), value 2 Event: time 1485333306.847098, type 4 (EV_MSC), code 4 (MSC_SCAN), value cd Event: time 1485333306.847098, type 1 (EV_KEY), code 106 (KEY_RIGHT), value 0 The same happens after the first sequence (first Fn press, then Right press), the value with KEY_END is 2 on press and then 0 on release. I tested this on kernel 4.8 (live Ubuntu 16.10) but I haven't tested it with the latest vanilla kernel just yet. I searched through linux-input archives and found some threads about repeating keys, but this looks like a different problem altogether. Also note that on my L321X I've upgraded the BIOS to the latest version (A08) long ago. The problem doesn't appear either on the Linux console or in Windows. Do you think this is something that could be fixed in the input driver? Regards, Ignacy -- Sex on TV doesn't hurt....unless you fall off. -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
