Re: Proposal: change keycode for scancode e0 32 from 150 to 172

[Hans de Goede <j.w.r.degoede@hhs.nl>]

H. Peter Anvin wrote:
> Hans de Goede wrote:
> > In order to be able to better test / develop this I've bought 2 cheap
> > such keyboards today, one ps2 and one both usb and ps2 capable.
> >
> > When comparing usb vs ps2 / testing the keycodes generated for the easy
> > access
> > keys on my trust (microsoft compatible) keyboard. I noticed the homepage
> > key sends keycode 150 with ps2 and 172 with USB, or for those who don't
> > know the keycodes by head with ps2 it sends KEY_WWW and with usb it
> > sends KEY_HOMEPAGE
>
> I just tested this using Microsoft Natural Keyboard Pro, which is a
> dual-mode (USB-PS/2) keyboard.
>
> This key is labelled Web/Home and has a picture of a house on the keycap.
>
> In PS/2 mode it reports E0 32 which gets converted to keycode 150.
> In USB mode it reports E0 02 which gets converted to keycode 172.

Thanks, that confirms that the ps/2 translation (which assumes a microsoft or 
compatible keyboard) is wrong.

> I don't know if it's the keyboard itself that's being inconsistent, or
> if it is the table in usbkbd.c that's broken (in which case it should be
> fixed to be consistent with the keyboard in PS/2 mode.)

See below.

> > I personally believe that the usb behaviour is correct and that the ps/2
> > code should be modified to match for consistency. The ps/2 scancode to
> > keycode mapping is set up to handle easy access / internet keys for
> > microsoft compatible keyboards. So what is the right code to send here,
> > tricky, see:
> > http://www.s2.com.br/s2arquivos/361/Imagens/555Image.jpg
> > http://www.keyboardco.com/keyboard_images/microsoft_ergonomic_keyboard_4000_black_usb_large.jpg
> >
> > The logo on the key is a homepage logo, the text below is www/homepage.
> > So what to send? I believe that for consistency with the usb codes send
> > it should be KEY_HOMEPAGE, but thats based on a sample of 1 usb
> > keyboard. Input on what other usb keyboards send for the key with the
> > homepage iocn is very much welcome.
>
> You seem to be of the opinion that "usb behaviour is correct", but don't
> give any motivation why usb should take precedence.  Offhand, I would
> expect there to be fewer translation layers for PS/2 and would therefore
> assume PS/2 is more inherently correct.

I'm of the opinion that the USB behaviour is correct, because usb generates the 
172 / KEY_HOMEPAGE in accordance with:
http://www.usb.org/developers/devclass_docs/Hut1_12.pdf
Page 84

Where as in the ps2 world there is no official scancode mapping for these 
special keys, hence I talk about microsoft and compatibles. Also the number of 
layers of translation in both cases is just 1: one table (ps2) versus one 
switch statement (usb)

Regards,

Hans
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