input system: EVIOCSABS(abs) ioctl disabled, why?

input system: EVIOCSABS(abs) ioctl disabled, why?

[Olav Kongas]

Hi,

When trying to feed calibration information to a touchscreen driver with
the EVIOCSABS(abs) ioctl command, I noticed that this command is disabled
in 2.6.7. Only after the modification given in the patch below it was
possible to use this ioctl command.

Why is the EVIOCSABS command disabled? I cannot imagine that nobody uses
or needs it. The touchscreen drivers have no good way of determining the
absolute limits themselves, do they?

Thanks in advance,
Olav


--- linux-2.6.7/drivers/input/evdev.c.or	2004-07-21 13:27:03.000000000 +0300
+++ linux-2.6.7/drivers/input/evdev.c	2004-07-21 15:53:46.000000000 +0300
@@ -284,7 +284,7 @@

 		default:

-			if (_IOC_TYPE(cmd) != 'E' || _IOC_DIR(cmd) != _IOC_READ)
+			if (_IOC_TYPE(cmd) != 'E' || (_IOC_DIR(cmd) != _IOC_READ && (cmd & ~ABS_MAX) !=  EVIOCSABS(0)))
 				return -EINVAL;

 			if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {

Re: input system: EVIOCSABS(abs) ioctl disabled, why?

[Vojtech Pavlik]

On Wed, Jul 28, 2004 at 03:41:28PM +0300, Olav Kongas wrote:

> When trying to feed calibration information to a touchscreen driver with
> the EVIOCSABS(abs) ioctl command, I noticed that this command is disabled
> in 2.6.7. Only after the modification given in the patch below it was
> possible to use this ioctl command.
> 
> Why is the EVIOCSABS command disabled? I cannot imagine that nobody uses

It's a bug. I'll fix it.

> or needs it.

Nobody uses it, surprisingly.

> The touchscreen drivers have no good way of determining the
> absolute limits themselves, do they?

Many do.

> Thanks in advance,
> Olav
> 
> --- linux-2.6.7/drivers/input/evdev.c.or	2004-07-21 13:27:03.000000000 +0300
> +++ linux-2.6.7/drivers/input/evdev.c	2004-07-21 15:53:46.000000000 +0300
> @@ -284,7 +284,7 @@
> 
>  		default:
> 
> -			if (_IOC_TYPE(cmd) != 'E' || _IOC_DIR(cmd) != _IOC_READ)
> +			if (_IOC_TYPE(cmd) != 'E' || (_IOC_DIR(cmd) != _IOC_READ && (cmd & ~ABS_MAX) !=  EVIOCSABS(0)))
>  				return -EINVAL;
> 
>  			if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR

Re: input system: EVIOCSABS(abs) ioctl disabled, why?

[Kristian Høgsberg]

Vojtech Pavlik wrote:
> On Wed, Jul 28, 2004 at 03:41:28PM +0300, Olav Kongas wrote:
> 
> 
>>When trying to feed calibration information to a touchscreen driver with
>>the EVIOCSABS(abs) ioctl command, I noticed that this command is disabled
>>in 2.6.7. Only after the modification given in the patch below it was
>>possible to use this ioctl command.
>>
>>Why is the EVIOCSABS command disabled? I cannot imagine that nobody uses
> 
> 
> It's a bug. I'll fix it.

On a related note - shouldn't there also be a EVIOCSLED, or am I missing 
something obvious?  How do you set keyboard LEDs?

Kristian

Re: input system: EVIOCSABS(abs) ioctl disabled, why?

[Lee Revell]

On Fri, 2004-07-30 at 22:31, Kristian Høgsberg wrote:
> Vojtech Pavlik wrote:
> > On Wed, Jul 28, 2004 at 03:41:28PM +0300, Olav Kongas wrote:
> > 
> > 
> >>When trying to feed calibration information to a touchscreen driver with
> >>the EVIOCSABS(abs) ioctl command, I noticed that this command is disabled
> >>in 2.6.7. Only after the modification given in the patch below it was
> >>possible to use this ioctl command.
> >>
> >>Why is the EVIOCSABS command disabled? I cannot imagine that nobody uses
> > 
> > 
> > It's a bug. I'll fix it.
> 
> On a related note - shouldn't there also be a EVIOCSLED, or am I missing 
> something obvious?  How do you set keyboard LEDs?
> 

Interesting you should mention keyboard LEDs.  Here is a patch that was
recently posted to replace the old, broken method of setting keyboard
lights (issue a command an busy-wait until you get an ACK) with an
improved one (using work queues and a semaphore).  It does not really
answer your question as such, but should be a good place to start.

http://lkml.org/lkml/2004/7/27/252

HTH,

Lee

Re: input system: EVIOCSABS(abs) ioctl disabled, why?

[Dmitry Torokhov]

On Friday 30 July 2004 09:31 pm, Kristian Høgsberg wrote:
> Vojtech Pavlik wrote:
> > On Wed, Jul 28, 2004 at 03:41:28PM +0300, Olav Kongas wrote:
> > 
> > 
> >>When trying to feed calibration information to a touchscreen driver with
> >>the EVIOCSABS(abs) ioctl command, I noticed that this command is disabled
> >>in 2.6.7. Only after the modification given in the patch below it was
> >>possible to use this ioctl command.
> >>
> >>Why is the EVIOCSABS command disabled? I cannot imagine that nobody uses
> > 
> > 
> > It's a bug. I'll fix it.
> 
> On a related note - shouldn't there also be a EVIOCSLED, or am I missing 
> something obvious?  How do you set keyboard LEDs?
> 

I think you can use KDSKBLED/KDSETLED ioctls, but I agree that that evdev
should also provide access to the same functions.

-- 
Dmitry

Re: input system: EVIOCSABS(abs) ioctl disabled, why?

[Vojtech Pavlik]

On Sat, Jul 31, 2004 at 04:31:34AM +0200, Kristian H??gsberg wrote:
> Vojtech Pavlik wrote:
> >On Wed, Jul 28, 2004 at 03:41:28PM +0300, Olav Kongas wrote:
> >
> >
> >>When trying to feed calibration information to a touchscreen driver with
> >>the EVIOCSABS(abs) ioctl command, I noticed that this command is disabled
> >>in 2.6.7. Only after the modification given in the patch below it was
> >>possible to use this ioctl command.
> >>
> >>Why is the EVIOCSABS command disabled? I cannot imagine that nobody uses
> >
> >
> >It's a bug. I'll fix it.
> 
> On a related note - shouldn't there also be a EVIOCSLED, or am I missing 
> something obvious?  How do you set keyboard LEDs?
 
You write() an LED event to the device. EVIOCSABS is intended for
modifying the absolute valuator range, not the value itself.

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR

Re: input system: EVIOCSABS(abs) ioctl disabled, why?

[Vojtech Pavlik]

On Fri, Jul 30, 2004 at 11:54:25PM -0500, Dmitry Torokhov wrote:
> On Friday 30 July 2004 09:31 pm, Kristian H?gsberg wrote:
> > Vojtech Pavlik wrote:
> > > On Wed, Jul 28, 2004 at 03:41:28PM +0300, Olav Kongas wrote:
> > > 
> > > 
> > >>When trying to feed calibration information to a touchscreen driver with
> > >>the EVIOCSABS(abs) ioctl command, I noticed that this command is disabled
> > >>in 2.6.7. Only after the modification given in the patch below it was
> > >>possible to use this ioctl command.
> > >>
> > >>Why is the EVIOCSABS command disabled? I cannot imagine that nobody uses
> > > 
> > > 
> > > It's a bug. I'll fix it.
> > 
> > On a related note - shouldn't there also be a EVIOCSLED, or am I missing 
> > something obvious?  How do you set keyboard LEDs?
> > 
> 
> I think you can use KDSKBLED/KDSETLED ioctls, but I agree that that evdev
> should also provide access to the same functions.
 
It does, see my previous e-mail.

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR

Re: input system: EVIOCSABS(abs) ioctl disabled, why?

[Kristian Høgsberg]

Vojtech Pavlik wrote:
...
>>On a related note - shouldn't there also be a EVIOCSLED, or am I missing 
>>something obvious?  How do you set keyboard LEDs?
> 
> You write() an LED event to the device. EVIOCSABS is intended for
> modifying the absolute valuator range, not the value itself.

Yeah, that works, thanks.

Kristian