HID: input: do not increment usages when a duplicate is found

This is something that bothered us from a long time. When hid-input
doesn't know how to map a usage, it uses *_MISC. But there is something
else which increments the usage if the evdev code is already used.

This leads to few issues:
- some devices may have their ABS_X mapped to ABS_Y if they export a bad
  set of usages (see the DragonRise joysticks IIRC -> fixed in a specific
  HID driver)
- *_MISC + N might (will) conflict with other defined axes (my Logitech
  H800 exports some multitouch axes because of that)
- this prevents to freely add some new evdev usages, because "hey, my
  headset will now report ABS_COFFEE, and it's not coffee capable".

So let's try to kill this nonsense, and hope we won't break too many
devices.

I my headset case, the ABS_MISC axes are created because of some
proprietary usages, so we might not break that many devices.

For backward compatibility, a quirk HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE
is created and can be applied to any device that needs this behavior.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/hid.h b/include/linux/hid.h
index 8da3e1f48195..0267aa5c1ea3 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -345,6 +345,7 @@ struct hid_item {
 #define HID_QUIRK_SKIP_OUTPUT_REPORT_ID         BIT(17)
 #define HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP  BIT(18)
 #define HID_QUIRK_HAVE_SPECIAL_DRIVER           BIT(19)
+#define HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE  BIT(20)
 #define HID_QUIRK_FULLSPEED_INTERVAL            BIT(28)
 #define HID_QUIRK_NO_INIT_REPORTS               BIT(29)
 #define HID_QUIRK_NO_IGNORE                     BIT(30)
@@ -502,6 +503,7 @@ struct hid_output_fifo {
 
 #define HID_STAT_ADDED          BIT(0)
 #define HID_STAT_PARSED         BIT(1)
+#define HID_STAT_DUP_DETECTED   BIT(2)
 
 struct hid_input {
         struct list_head list;