[PATCH] uinput: Allow for 0/0 min/max on absolute axes.

[Peter Hutterer <peter.hutterer@who-t.net>]

Some devices provide absolute axes with min/max of 0/0 (e.g. wacom's
ABS_MISC axis). Current uinput restrictions do not allow duplication of
these devices and require hacks in userspace to work around this.

If the kernel accepts physical devices with a min/max of 0/0, uinput
shouldn't disallow the same range.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
---
 drivers/input/misc/uinput.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index b941078..d7cc037 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -301,10 +301,14 @@ static int uinput_validate_absbits(struct input_dev *dev)
 	int retval = 0;
 
 	for (cnt = 0; cnt < ABS_CNT; cnt++) {
+		int min, max;
 		if (!test_bit(cnt, dev->absbit))
 			continue;
 
-		if (input_abs_get_max(dev, cnt) <= input_abs_get_min(dev, cnt)) {
+		min = input_abs_get_min(dev, cnt);
+		max = input_abs_get_max(dev, cnt);
+
+		if ((min != 0 || max != 0) && max <= min) {
 			printk(KERN_DEBUG
 				"%s: invalid abs[%02x] min:%d max:%d\n",
 				UINPUT_NAME, cnt,
-- 
1.7.4.2