[OE-core] [PATCH] udev: generalize the check in touchscreen rule

[Koen Kooi]

Op 11 apr. 2012, om 12:16 heeft Richard Purdie het volgende geschreven:

> On Wed, 2012-04-11 at 10:59 +0200, Andrea Adami wrote:
>> On Mon, Apr 2, 2012 at 11:35 PM, Andrea Adami <andrea.adami at gmail.com> wrote:
>>> * The actual rule only works for devices reporting ts pressure
>>> * and ignores the other touchscreens (happens e.g. on ipaq h1940).
>>> * a0,1,*18   a = absolute axes (ABS_X 0x00 ABS_Y 0x01 ABS_PRESSURE 0x18)
>>> * (see include/linux/input.h)
>>> *
>>> * Guidelines for touchscreen seem suggesting only ABS_X and ABS_Y are mandatory
>>> * (http://kernel.org/doc/Documentation/input/event-codes.txt)
>>> *
>>> * Bump PR
>>> 
>>> Signed-off-by: Andrea Adami <andrea.adami at gmail.com>
>>> ---
>>> meta/recipes-core/udev/udev/local.rules |    3 +--
>>> meta/recipes-core/udev/udev_164.bb      |    2 +-
>>> 2 files changed, 2 insertions(+), 3 deletions(-)
>>> 
>>> diff --git a/meta/recipes-core/udev/udev/local.rules b/meta/recipes-core/udev/udev/local.rules
>>> index 625e49a..49e8d28 100644
>>> --- a/meta/recipes-core/udev/udev/local.rules
>>> +++ b/meta/recipes-core/udev/udev/local.rules
>>> @@ -31,5 +31,4 @@ KERNEL=="rtc0", SYMLINK+="rtc"
>>> ACTION=="add", DEVPATH=="/devices/*", ENV{MODALIAS}=="?*", RUN+="/sbin/modprobe $env{MODALIAS}"
>>> 
>>> # Create a symlink to any touchscreen input device
>>> -SUBSYSTEM=="input", KERNEL=="event[0-9]*", ATTRS{modalias}=="input:*-e0*,3,*a0,1,*18,*", SYMLINK+="input/touchscreen0"
>>> -
>>> +SUBSYSTEM=="input", KERNEL=="event[0-9]*", ATTRS{modalias}=="input:*-e0*,3,*a0,1,*", SYMLINK+="input/touchscreen0"
>>> diff --git a/meta/recipes-core/udev/udev_164.bb b/meta/recipes-core/udev/udev_164.bb
>>> index c5813ec..0462ff2 100644
>>> --- a/meta/recipes-core/udev/udev_164.bb
>>> +++ b/meta/recipes-core/udev/udev_164.bb
>>> @@ -1,6 +1,6 @@
>>> include udev.inc
>>> 
>>> -PR = "r13"
>>> +PR = "r14"
>>> 
>>> SRC_URI += "file://udev-166-v4l1-1.patch"
>>> 
>>> --
>>> 1.7.3.4
>>> 
>> 
>> Bump
>> 
>> I'm not linux-input specialist but this fix looks rather harmless.
> 
> I'm not 100% convinced about that. There needs to be some mechanism to
> signal to the system when there is pressure applied to the screen and
> when pressure was released. I think there are two ways you can do this,
> BTN_TOUCH and ABS_PRESSURE. Regardless of what the input events codes
> say, I'm really more interested in what tslib accepts.
> 
> This code has been like this for a long time and I'm surprised that if
> there were issues it wasn't patched long before now. I'm therefore left
> wondering if the touchscreen driver you're using is doing the right
> things.

FWIW, we had a similar patch to udev in the TI overlay, but the kernel team fixed the ts driver in the kernel a few weeks later.  Qt and X11 can use evdev natively nowadays, so tslib usage is on its way out.

regards,

Koen