diff options
| author | Jason Gerecke <killertofu@gmail.com> | 2015-10-07 16:54:21 -0700 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2015-10-21 13:13:11 +0200 |
| commit | 499522c8c015de995aabce3d0f0bf4b9b17f44c3 (patch) | |
| tree | 71ee15c9be4502d28e4618e7316ce29299f606a7 /drivers | |
| parent | e8e88438008375b17561dcc6a22abc24decf04ac (diff) | |
| download | linux-499522c8c015de995aabce3d0f0bf4b9b17f44c3.tar.bz2 | |
HID: wacom: Tie cached HID_DG_CONTACTCOUNT indices to report ID
The cached indicies 'cc_index' and 'cc_value_index' introduced in 1b5d514
are only valid for a single report ID. If a touchscreen has multiple
reports with a HID_DG_CONTACTCOUNT usage, its possible that the values
will not be correct for the report we're handling, resulting in an
incorrect value for 'num_expected'. This has been observed with the Cintiq
Companion 2.
To address this, we store the ID of the report those indicies are valid
for in a new 'cc_report' variable. Before using them to get the expected
contact count, we first check if the ID of the report we're processing
matches 'cc_report'. If it doesn't, we update the indicies to point to
the HID_DG_CONTACTCOUNT usage of the current report (if it has one).
Cc: stable@vger.kernel.org
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/hid/wacom_wac.c | 26 | ||||
| -rw-r--r-- | drivers/hid/wacom_wac.h | 1 |
2 files changed, 27 insertions, 0 deletions
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c index 0215ab62bb93..9c3b14496c97 100644 --- a/drivers/hid/wacom_wac.c +++ b/drivers/hid/wacom_wac.c @@ -1628,6 +1628,7 @@ static void wacom_wac_finger_usage_mapping(struct hid_device *hdev, wacom_map_usage(input, usage, field, EV_KEY, BTN_TOUCH, 0); break; case HID_DG_CONTACTCOUNT: + wacom_wac->hid_data.cc_report = field->report->id; wacom_wac->hid_data.cc_index = field->index; wacom_wac->hid_data.cc_value_index = usage->usage_index; break; @@ -1715,6 +1716,31 @@ static void wacom_wac_finger_pre_report(struct hid_device *hdev, struct wacom_wac *wacom_wac = &wacom->wacom_wac; struct hid_data* hid_data = &wacom_wac->hid_data; + if (hid_data->cc_report != 0 && + hid_data->cc_report != report->id) { + int i; + + hid_data->cc_report = report->id; + hid_data->cc_index = -1; + hid_data->cc_value_index = -1; + + for (i = 0; i < report->maxfield; i++) { + struct hid_field *field = report->field[i]; + int j; + + for (j = 0; j < field->maxusage; j++) { + if (field->usage[j].hid == HID_DG_CONTACTCOUNT) { + hid_data->cc_index = i; + hid_data->cc_value_index = j; + + /* break */ + i = report->maxfield; + j = field->maxusage; + } + } + } + } + if (hid_data->cc_index >= 0) { struct hid_field *field = report->field[hid_data->cc_index]; int value = field->value[hid_data->cc_value_index]; diff --git a/drivers/hid/wacom_wac.h b/drivers/hid/wacom_wac.h index 1e270d401e18..809c03e34f74 100644 --- a/drivers/hid/wacom_wac.h +++ b/drivers/hid/wacom_wac.h @@ -198,6 +198,7 @@ struct hid_data { int width; int height; int id; + int cc_report; int cc_index; int cc_value_index; int num_expected; |