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>
diff --git a/drivers/hid/wacom_wac.h b/drivers/hid/wacom_wac.h
index 1e270d4..809c03e 100644
--- a/drivers/hid/wacom_wac.h
+++ b/drivers/hid/wacom_wac.h
@@ -198,6 +198,7 @@
int width;
int height;
int id;
+ int cc_report;
int cc_index;
int cc_value_index;
int num_expected;