Acecad USB Tablet: usbmouse takeover and odd motion

Acecad USB Tablet: usbmouse takeover and odd motion

[Giuseppe Bilotta]

Hello all,

I have a Medi@com-branded Acecad USB Tablet and I've been trying for a
while to set it up to work fine under Linux, without very much
success. I've been using the stock Debian kernel (2.6.18), but also
tried rolling my own 2.6.x git series (latest tried a 2.6.21-rc7 just
this evening). The problems still appear.

The first problem is that the usbmouse and usbhid drivers take control
of the device, so that when I plug it in the tablet appears as a
mouse, with extremely funny effects (cursor jumping around, buttons
clicking out of nowhere, and other strange stuff).I have to rmmod
usbmouse and usbhid and then re-modprobe acecad to get proper data
from the tablet (where by 'proper' I mean that input-events reports
apparently correct values for X, Y, pressure and keypresses.

So the first question is: is there a way to let acecad control the
tablet without blacklisting usbmouse and usbhid?

The second question is more user-space related, so this might not be
the right place to ask; feel free to address me to more appropriate
discussion places for the following issues.

Basically, in console the tablet works 'almost' correctly, with gpm
set to read from /dev/input/mice with protocol autops2: if I wrap the
pen from one side to the opposite side without passing through the
tablet, the cursor jumps to the correct place. However, if I move the
pen across the tablet, the motion seems to be always either too fast
or too slow, so that either the mouse reaches the opposite side of the
screen while I'm still halfway throught the tablet, or conversely.

In X (X.org 7.2.0), I cannot use the acecad driver (it fails to
initialize the device, probably because it's managed by the kernel
already, I assume), so I have to use the evdev driver version 1.1.0
(xinput version 1.2.0). With this setup, programs such as Inkscape or
Gimp 'know' that the Tablet is a tablet and correctly configure the
3rd axis for pressure, but the cursor movement is extremely jerky, and
neither pressure nor button presses seem to be received, making the
tablet essentially useless.

I've tried setting CONFIG_INPUT_MOUSEDEV_SCREEN_{X,Y} to match my
screen resolution {1600,1200}, but this has barely improved the motion
jerkiness, if at all (Why is there a need for the kernel to know the
resolution used by X, anyway? Shouldn't userspace itself take care of
scaling input->screen coordinates?) Moreover, it hasn't solved the
missing buttons/pressure.

 Is this an evdev/X bug, a kernel limitation, neither or both?

-- 
Giuseppe "Oblomov" Bilotta

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Jiri Kosina]

On Fri, 20 Apr 2007, Giuseppe Bilotta wrote:

> The first problem is that the usbmouse and usbhid drivers take control 
> of the device, so that when I plug it in the tablet appears as a mouse, 
> with extremely funny effects (cursor jumping around, buttons clicking 
> out of nowhere, and other strange stuff).I have to rmmod usbmouse and 
> usbhid and then re-modprobe acecad to get proper data from the tablet 
> (where by 'proper' I mean that input-events reports apparently correct 
> values for X, Y, pressure and keypresses.

Hi Giuseppe,

could you please send me the product ID of the hardware in question? (you 
could get it for example by running lsusb). Currently the usbhid driver 
blacklists just product ids 0x0004 and 0x0008 (so that for these product 
ids, the HID driver doesn't claim the device and lets other driver - 
acecad - to claim it). I guess you have some newer version of the device, 
so just adding it to blacklist should suffice.

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Giuseppe Bilotta]

On 4/20/07, Jiri Kosina <jkosina@suse.cz> wrote:
> On Fri, 20 Apr 2007, Giuseppe Bilotta wrote:
>
> > The first problem is that the usbmouse and usbhid drivers take control
> > of the device, so that when I plug it in the tablet appears as a mouse,
> > with extremely funny effects (cursor jumping around, buttons clicking
> > out of nowhere, and other strange stuff).I have to rmmod usbmouse and
> > usbhid and then re-modprobe acecad to get proper data from the tablet
> > (where by 'proper' I mean that input-events reports apparently correct
> > values for X, Y, pressure and keypresses.
>
> Hi Giuseppe,
>
> could you please send me the product ID of the hardware in question? (you
> could get it for example by running lsusb). Currently the usbhid driver
> blacklists just product ids 0x0004 and 0x0008 (so that for these product
> ids, the HID driver doesn't claim the device and lets other driver -
> acecad - to claim it). I guess you have some newer version of the device,
> so just adding it to blacklist should suffice.

Hello Jiri,

lsusb claims:

Bus 002 Device 003: ID 0460:0004 Ace Cad Enterprise Co., Ltd

and according to hid-core.c this *is* a blacklisted ID ...

-- 
Giuseppe "Oblomov" Bilotta

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Jiri Kosina]

On Fri, 20 Apr 2007, Giuseppe Bilotta wrote:

> > could you please send me the product ID of the hardware in question? 
> > (you could get it for example by running lsusb). Currently the usbhid 
> > driver blacklists just product ids 0x0004 and 0x0008 (so that for 
> > these product ids, the HID driver doesn't claim the device and lets 
> > other driver - acecad - to claim it). I guess you have some newer 
> > version of the device, so just adding it to blacklist should suffice.
> lsusb claims:
> Bus 002 Device 003: ID 0460:0004 Ace Cad Enterprise Co., Ltd
> and according to hid-core.c this *is* a blacklisted ID ...

Yes, so it definitely should be ignored and not claimed by the usbhid 
subsystem.

Could you please verify in /sys/bus/usb/drivers/usbhid whether this device 
is really claimed by the usbhid driver? Do you have other HID devices in 
the system?

-- 
Jiri Kosina

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Giuseppe Bilotta]

On 4/20/07, Jiri Kosina <jkosina@suse.cz> wrote:
> On Fri, 20 Apr 2007, Giuseppe Bilotta wrote:
>
> > lsusb claims:
> > Bus 002 Device 003: ID 0460:0004 Ace Cad Enterprise Co., Ltd
> > and according to hid-core.c this *is* a blacklisted ID ...
>
> Yes, so it definitely should be ignored and not claimed by the usbhid
> subsystem.

> Could you please verify in /sys/bus/usb/drivers/usbhid whether this device
> is really claimed by the usbhid driver? Do you have other HID devices in
> the system?

Sorry, it seems I was wrong, it's not usbhid but usbmouse taking over.
After a fresh plug (e.g. at bootup) I get the following:

dmesg:

usb 1-1: new low speed USB device using uhci_hcd and address 2
usb 1-1: configuration #1 chosen from 1 choice
input: ACECAD USB Graphics Tablet  as /class/input/input4
usbcore: registered new interface driver usbmouse
drivers/usb/input/usbmouse.c: v1.6:USB HID Boot Protocol mouse driver
usbcore: registered new interface driver hiddev
usbcore: registered new interface driver usbhid
drivers/usb/input/hid-core.c: v2.6:USB HID core driver
usbcore: registered new interface driver usb_acecad
drivers/usb/input/acecad.c: v3.2:USB Acecad Flair tablet driver

/proc/bus/input/devices

I: Bus=0003 Vendor=0460 Product=0004 Version=0130
N: Name="ACECAD USB Graphics Tablet "
P: Phys=usb-0000:00:1d.0-1/input0
S: Sysfs=/class/input/input4
H: Handlers=mouse2 event4
B: EV=7
B: KEY=1f0000 0 0 0 0 0 0 0 0
B: REL=103

ls /sys/bus/usb/drivers/usbmouse

total 0
lrwxrwxrwx 1 root root    0 2007-04-20 17:30 1-1:1.0 ->
../../../../devices/pci0000:00/0000:00:1d.0/usb1/1-1/1-1:1.0
--w------- 1 root root 4096 2007-04-20 17:30 bind
lrwxrwxrwx 1 root root    0 2007-04-20 17:30 module ->
../../../../module/usbmouse
--w------- 1 root root 4096 2007-04-20 17:30 new_id
--w------- 1 root root 4096 2007-04-20 17:30 unbind

So it seems that the greedy driver is usbmouse. I'm adding Vojtech to
the CC: list, since he's listed as the usbmouse author.

Notice that if I rmmod usbmouse and rmmod acecad and then modprobe
acecad again (or maybe I should learn to use the bind/unbind features)
without unplugging the tablet, I get more 'correct'
/proc/bus/input/devices

I: Bus=0003 Vendor=0460 Product=0004 Version=0130
N: Name="ACECAD USB Graphics Tablet "
P: Phys=usb-0000:00:1d.0-1/input0
S: Sysfs=/class/input/input8
H: Handlers=mouse2 event4
B: EV=b
B: KEY=1c01 0 70000 0 0 0 0 0 0 0 0
B: ABS=1000003

and ls /sys/bus/usb/drivers/*

/sys/bus/usb/drivers/hiddev:
bind
module
new_id
unbind

/sys/bus/usb/drivers/hub:
1-0:1.0
2-0:1.0
bind
module
new_id
unbind

/sys/bus/usb/drivers/usb:
1-1
bind
module
unbind
usb1
usb2

/sys/bus/usb/drivers/usb_acecad:
1-1:1.0
bind
module
new_id
unbind

/sys/bus/usb/drivers/usbfs:
bind
module
new_id
unbind

/sys/bus/usb/drivers/usbhid:
bind
module
new_id
unbind

so just letting usbmouse ignore the device (or maybe have acecad claim
it from usbmouse automagically, if this kind of thing is possible)
should fix the kernel side of the issue (xinput/evdev on X is still
confused by the tablet, even if do the driver gimmick before starting
X, but I'll take that over to the xorg mailing list as soon as I've
fixed the thing kernel side).

Any suggestions or patches welcome.

-- 
Giuseppe "Oblomov" Bilotta

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Dmitry Torokhov]

On 4/20/07, Giuseppe Bilotta <giuseppe.bilotta@gmail.com> wrote:
>
> Sorry, it seems I was wrong, it's not usbhid but usbmouse taking over.
> After a fresh plug (e.g. at bootup) I get the following:
>

Well, the question is - why do you have usbmouse module on your system?

-- 
Dmitry

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Giuseppe Bilotta]

On 4/20/07, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> On 4/20/07, Giuseppe Bilotta <giuseppe.bilotta@gmail.com> wrote:
> >
> > Sorry, it seems I was wrong, it's not usbhid but usbmouse taking over.
> > After a fresh plug (e.g. at bootup) I get the following:
> >
>
> Well, the question is - why do you have usbmouse module on your system?

Stock Debian kernel 2.6.18 comes with it.

With my custom kernels I can probably skip compiling it at all, if you
so suggest; should I blacklist it for the distro kernel? Or is there a
chance that some random USB mouse plugged in would fail to function by
doing so?

(sorry for the double-send, forgot to reply to all)

-- 
Giuseppe "Oblomov" Bilotta

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Vojtech Pavlik]

On Fri, Apr 20, 2007 at 06:09:55PM +0200, Giuseppe Bilotta wrote:
> On 4/20/07, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> >On 4/20/07, Giuseppe Bilotta <giuseppe.bilotta@gmail.com> wrote:
> >>
> >> Sorry, it seems I was wrong, it's not usbhid but usbmouse taking over.
> >> After a fresh plug (e.g. at bootup) I get the following:
> >>
> >
> >Well, the question is - why do you have usbmouse module on your system?
> 
> Stock Debian kernel 2.6.18 comes with it.
> 
> With my custom kernels I can probably skip compiling it at all, if you
> so suggest; should I blacklist it for the distro kernel? Or is there a
> chance that some random USB mouse plugged in would fail to function by
> doing so?
 
usbmouse and usbkbd are only intended for embedded systems where the
full usbhid doesn't fit and for testing purposes: Normal distros
shouldn't have them enabled.

-- 
Vojtech Pavlik
Director SuSE Labs

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Giuseppe Bilotta]

On 4/20/07, Vojtech Pavlik <vojtech@suse.cz> wrote:
> On Fri, Apr 20, 2007 at 06:09:55PM +0200, Giuseppe Bilotta wrote:
> > On 4/20/07, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> > >On 4/20/07, Giuseppe Bilotta <giuseppe.bilotta@gmail.com> wrote:
> > >>
> > >> Sorry, it seems I was wrong, it's not usbhid but usbmouse taking over.
> > >> After a fresh plug (e.g. at bootup) I get the following:
> > >>
> > >
> > >Well, the question is - why do you have usbmouse module on your system?
> >
> > Stock Debian kernel 2.6.18 comes with it.
> >
> > With my custom kernels I can probably skip compiling it at all, if you
> > so suggest; should I blacklist it for the distro kernel? Or is there a
> > chance that some random USB mouse plugged in would fail to function by
> > doing so?
>
> usbmouse and usbkbd are only intended for embedded systems where the
> full usbhid doesn't fit and for testing purposes: Normal distros
> shouldn't have them enabled.

Oh, I see. I'll blacklist those modules, maybe also issue a ticket on
the Debian BTS.

Thanks all.

-- 
Giuseppe "Oblomov" Bilotta

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Jiri Kosina]

On Fri, 20 Apr 2007, Giuseppe Bilotta wrote:

> Oh, I see. I'll blacklist those modules, maybe also issue a ticket on 
> the Debian BTS.

If Debian enables usbmouse and usbkbd by default in their standard 
kernels, would you be so kind and raise a proper ticket on them not to do 
so? Thanks.

This also makes me to speed up with one of my items on TODO list - rename 
usbmouse and usbkbd to something that wouldn't be so confusing and 
wouldn't make people think that they should enable these drivers if they 
want support for USB keyboards/mice. Will queue this for 2.6.22.

-- 
Jiri Kosina
SUSE Labs

Re: Acecad USB Tablet: usbmouse takeover and odd motion

[Giuseppe Bilotta]

On 4/21/07, Jiri Kosina <jkosina@suse.cz> wrote:
> On Fri, 20 Apr 2007, Giuseppe Bilotta wrote:
>
> > Oh, I see. I'll blacklist those modules, maybe also issue a ticket on
> > the Debian BTS.
>
> If Debian enables usbmouse and usbkbd by default in their standard
> kernels, would you be so kind and raise a proper ticket on them not to do
> so? Thanks.
>
> This also makes me to speed up with one of my items on TODO list - rename
> usbmouse and usbkbd to something that wouldn't be so confusing and
> wouldn't make people think that they should enable these drivers if they
> want support for USB keyboards/mice. Will queue this for 2.6.22.

Actually, I just found out that usbmouse and usbkbd are in the
blacklist file (/etc/modprobe.d/blacklist), so the fact that they are
being called reveals some kind of fscked up setup on my side. I'll try
to fix that, sorry for the noise.


-- 
Giuseppe "Oblomov" Bilotta