Linux 4.5 Input Updates Bring Changes Even For PS/2 Mice

[phoronix]

Phoronix: Linux 4.5 Input Updates Bring Changes Even For PS/2 Mice

If you still are relying upon a PS/2 mouse, it really is time to think about upgrading to a USB mouse, but keep reading as there are some changes with Linux 4.5...

http://www.phoronix.com/scan.php?page=news_item&px=Linux-4.5-Input-Pull

[eydee]

Not sure why the article implies that there's something wrong with a PS/2 mouse. For the end user, there is absolutely no difference. Or wait, there is one, one more free USB slot...

[JasonBorden79]

I just purchased a laptop and it uses a Synaptics PS/2 touchpad so I'd say PS/2 is still alive in some regards.

[Azrael5]

though modern systems implement only one ps2 port, it is stated as this port provides benefit at least on ps2 keyboard because of irq and busmaster avoiding polling.

[Delgarde]

I just purchased a laptop and it uses a Synaptics PS/2 touchpad so I'd say PS/2 is still alive in some regards.

Yes, I think that's something that the snide commentary overlooks. PS/2 for peripherals may be more or less dead (though mobo makers persist in shipping with support for them)... but it's still fairly commonly used for integrated parts on laptops.

[Serafean]

Why should I drop PS/2? It's a perfectly valid simple and working keyboard/mouse protocol. I had the opportunity to implement it, fully in hardware. I dare you to do that with the USB HID protocol... For a basic mouse or keyboard, USB is definitely overkill. Oh and PS/2 is lighter on the CPU.

[cjcox]

There are a plethora of chicken-egg scenarios with USB (critical) input devices. And pretty much none for PS2. Can we buy the Linux devs some real hardware and/or real scenarios to test with? I'm sorry but this is sort of "duh".... I don't want to have "Linux devs, killing Linux since 2015" printed on a T-shirt.

[ruthan]

Especially with intel USB3 driver, i had few issues with linux live cd etc, so PS/2 is still actual, eve Windows have similar problems, before proper drivers are installed..
Im still using WinXP in dual boot just for few thing are inst any intel USB3 driver at all or maybe some not official.

[Techwolf]

PS/2 has less lag then USB. For gamers, that is importment.

[tajjada]

PS/2 is a much better protocol for keyboards. It is interrupt-based rather than polling-based, hence, less strain on the CPU and less latency (can be important for games).

Additionally, PS/2 supports true n-key rollover (you can press as many keys as you want on your keyboard simultaneously and all will register correctly), while USB only supports up to 6 keys being pressed simultaneously. In some scenarios, this can be a deal-breaker.

My keyboard, for instance, has circuitry capable of n-key rollover, but it only works if I connect it to my PC over PS/2. The USB connection limits it to 6. I have seen keyboards that try to do fancy trickery to emulate it on USB (my friend has one), and it sorta works, but breaks other things ...

And keep in mind that not all keyboards are meant for typing characters. There are plenty of specialised keyboards that have keys for controlling various devices or systems or dispatching commands.

PS/2 is an elegant and simple protocol that does its job very well. No need to be so harsh on it. USB is great for other reasons (one connection that can be used for anything (it is called Universal Serial Bus for a reason) from storage to printers to input devices ... all with one driver stack and one protocol, etc...), but PS/2 still has its place.

I could go on about mice/pointing devices as well, although I don't think that is necessary. Suffice to say, PS/2 is commonly used today for the internal connections of integrated devices like laptop touchpads, again, for its simplicity.

And please, Michael, be more neutral in your articles. It is somewhat expected from a professional journalist like you. Write your articles in a neutral tone and point of view, and share objective facts rather than strongly biased personal opinions. The negativity in this article was really uncalled for. About 2/3s of the text in this article was really not necessary, and did not provide any objective information; it only kept bashing the PS/2 protocol for no reason other than it being old (from the 1980s).