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| author | Jason Gerecke <killertofu@gmail.com> | 2016-07-21 16:10:46 (GMT) |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2016-08-11 20:37:13 (GMT) |
| commit | 003f50ab673c241a5596c05c88fd25ba71db086d (patch) | |
| tree | 59681d43d7e07077e7e5a06a21f3ef64854d0da3 /drivers/hid/wacom_wac.h | |
| parent | 08fc94733211f94755dd15028fb0a0129310fb5d (diff) | |
| download | linux-003f50ab673c241a5596c05c88fd25ba71db086d.tar.xz | |
HID: wacom: Update last_slot_field during pre_report phase
If a touchscreen contains both multitouch and single-touch reports in its
descriptor in that order, the driver may overwrite information it saved
about the format of the multitouch report. This can cause the report
processing code to get tripped up and send an incorrect event stream to
userspace.
In particular, this can cause last_slot_field to be overwritten with the
result that the driver prematurely assumes it has finished processing a
slot and sending the ABS_MT_SLOT event at the wrong point in time,
associating events for the current contact with the following contact
instead.
To prevent this from occurring, we update the value of last_slot_field
durring the pre_report phase to ensure that it is correct for the report
that is to be processed.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Ping Cheng <pingc@wacom.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid/wacom_wac.h')
| -rw-r--r-- | drivers/hid/wacom_wac.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/hid/wacom_wac.h b/drivers/hid/wacom_wac.h index 53d1653..b794e80 100644 --- a/drivers/hid/wacom_wac.h +++ b/drivers/hid/wacom_wac.h @@ -185,7 +185,6 @@ struct wacom_features { int pktlen; bool check_for_hid_type; int hid_type; - int last_slot_field; }; struct wacom_shared { @@ -214,6 +213,7 @@ struct hid_data { int cc_report; int cc_index; int cc_value_index; + int last_slot_field; int num_expected; int num_received; }; |