[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: gpm effectively turns my mouse into a Microsoft mouse



Eric Hanchrow <offby1@blarg.net>:

> I have discovered, through trial and error, that by default, the boot
> floppies install gpm, and that gpm sets /dev/mouse to be a symlink to
> /dev/gpmdata.  Nothing wrong with that, but I notice that X only works
> properly if I tell it that my mouse talks the Microsoft mouse
> protocol.  Nothing particularly wrong with that either, except that if
> I don't install gpm (and point /dev/mouse to /dev/psaux), I need to
> tell X that my mouse uses the PS/2 protocol.  Over the years I've come
> to learn that my mouse -- which is a Microsoft mouse that says "Mouse
> Port Compatible Mouse 2.1A" on the bottom -- talks the "PS/2"
> protocol, and so I've formed a habit of telling X that.  But now comes
> gpm, which apparently changes it to the Microsoft protocol.
> 
> So: I don't mind that gpm is doing that -- it probably has a good
> reason -- but I wish something had warned me about it.  I wasted a lot
> of time wondering why my mouse pointer was moving erratically; if I'd
> seen a message from gpm when it installed itself, saying "Note: if you
> install X, tell it that your mouse talks the Microsoft protocol", that
> would have saved some time.
> 
> Should the boot floppies be responsible for this warning, or does this
> sound like a wishlist bug for gpm?

I remember that /dev/gpmdata used always to be MouseSystems ("msc").
According to gpg -help (version 1.17.5 on Red Hat) the default is
still MouseSystems:

    -R mouse-type    enter repeater mode. X should read /dev/gpmdata
                     like it was a mouse-type device.  Default is MouseSystems.
                     You can also specify "raw" to relay the raw device data.

So, are you sure that /dev/gpmdata is using the MicroSoft protocol
("ms")?

Perhaps Debian's gpm package could issue a helpful message, but I
would have thought that -R msc is a good default, better than -R ms,
because that protocol doesn't work very well with button 2, and better
than -R raw, because gpm tends to support a bigger range of pointing
devices than the X servers. On the other hand, gpm no longer has an
upstream maintainer, so that might change ...

(I submitted a patch to gpm to add -t ms+, which lets you reset the
state of button 2 by pressing buttons 1 and 3 together. But I no
longer use that mouse type, because in the meantime I have discovered
that most MS mice can be converted into MSC mice with a simple bit of
soldering, and, since they only cost a few euros, it's not a big risk
to try it, though I'm so clumsy I could burn my finger, I suppose ...)

Edmund


Reply to: