diff options
author | Benjamin Tissoires <benjamin.tissoires@redhat.com> | 2017-12-08 15:28:18 +0100 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2018-04-17 14:08:54 +0200 |
commit | 190d7f02ce8ef6774a69d3ec18c288c8a9601a4e (patch) | |
tree | 4953de950ebd7fa3aaf9cd4e4c94fc1c34aa59f3 /drivers | |
parent | e8403b493fd5180e351ca67eb66406d95dadcd0b (diff) | |
download | linux-190d7f02ce8ef6774a69d3ec18c288c8a9601a4e.tar.bz2 |
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>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/hid/hid-input.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 6836a856c243..04056773102e 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1100,8 +1100,31 @@ mapped: set_bit(usage->type, input->evbit); - while (usage->code <= max && test_and_set_bit(usage->code, bit)) - usage->code = find_next_zero_bit(bit, max + 1, usage->code); + /* + * This part is *really* controversial: + * - HID aims at being generic so we should do our best to export + * all incoming events + * - HID describes what events are, so there is no reason for ABS_X + * to be mapped to ABS_Y + * - HID is using *_MISC+N as a default value, but nothing prevents + * *_MISC+N to overwrite a legitimate even, which confuses userspace + * (for instance ABS_MISC + 7 is ABS_MT_SLOT, which has a different + * processing) + * + * If devices still want to use this (at their own risk), they will + * have to use the quirk HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE, but + * the default should be a reliable mapping. + */ + while (usage->code <= max && test_and_set_bit(usage->code, bit)) { + if (device->quirks & HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE) { + usage->code = find_next_zero_bit(bit, + max + 1, + usage->code); + } else { + device->status |= HID_STAT_DUP_DETECTED; + goto ignore; + } + } if (usage->code > max) goto ignore; @@ -1611,6 +1634,8 @@ int hidinput_connect(struct hid_device *hid, unsigned int force) INIT_LIST_HEAD(&hid->inputs); INIT_WORK(&hid->led_work, hidinput_led_worker); + hid->status &= ~HID_STAT_DUP_DETECTED; + if (!force) { for (i = 0; i < hid->maxcollection; i++) { struct hid_collection *col = &hid->collection[i]; @@ -1677,6 +1702,10 @@ int hidinput_connect(struct hid_device *hid, unsigned int force) goto out_unwind; } + if (hid->status & HID_STAT_DUP_DETECTED) + hid_dbg(hid, + "Some usages could not be mapped, please use HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE if this is legitimate.\n"); + return 0; out_unwind: |